MI ucontext_t and x86 MD parts.
Kernel allocates the structures on the stack, and not clearing
reserved fields and paddings causes leakage.
Noted and discussed with: bde
MFC after: 2 weeks
should_yield(). Use this in various places. Encapsulate the common
case of check-and-yield into a new function maybe_yield().
Change several checks for a magic number of iterations to use
should_yield() instead.
MFC after: 1 week
be used by linuxolator itself.
Move linux_wait4() to MD path as it requires native struct
rusage translation to struct l_rusage on linux32/amd64.
MFC after: 1 Month.
when FPU is in use.
Reported by: Marc UBM Bocklet (ubm dot freebsd at googlemail dot com)
Tested by: b. f. (bf1783 at googlemail dot com)
MFC after: 3 days
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.
sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.
Reported and tested by: az
Reviewed by: alc, jhb
MFC after: 1 week
- Only check largs->num against max_ldt_segment on amd64 for I386_SET_LDT
when descriptors are provided. Specifically, allow the 'start == 0'
and 'num == 0' special case used to free all LDT entries that previously
failed with EINVAL.
Submitted by: clang via rdivacky (some of 1)
Reviewed by: kib
Compile sys/dev/mem/memutil.c for all supported platforms and remove now
unnecessary dev_mem_md_init(). Consistently define mem_range_softc from
mem.c for all platforms. Add missing #include guards for machine/memdev.h
and sys/memrange.h. Clean up some nearby style(9) nits.
MFC after: 1 month
started to execute, it seems that the corresponding ISR bit in the "old"
local APIC can be cleared. This causes the local APIC interrupt routine
to fail to find an interrupt to service. Rather than panic'ing in this
case, simply return from the interrupt without sending an EOI to the
local APIC. If there are any other pending interrupts in other ISR
registers, the local APIC will assert a new interrupt.
Tested by: steve
architecture macros (__mips_n64, __powerpc64__) when 64 bit types (and
corresponding macros) are different from 32 bit. [1]
Correct the type of INT64_MIN, INT64_MAX and UINT64_MAX.
Define (U)INTMAX_C as an alias for (U)INT64_C matching the type definition
for (u)intmax_t. Do this on all architectures for consistency.
Suggested by: bde [1]
Approved by: kib (mentor)
of (unsigned) int __attribute__((__mode__(__DI__))). This aligns better
with macros such as (U)INT64_C, (U)INT64_MAX, etc. which assume (u)int64_t
has type (unsigned) long long.
The mode attribute was used because long long wasn't standardised until
C99. Nowadays compilers should support long long and use of the mode
attribute is discouraged according to GCC Internals documentation.
The type definition has to be marked with __extension__ to support
compilation with "-std=c89 -pedantic".
Discussed with: bde
Approved by: kib (mentor)
On some architectures UCHAR_MAX and USHRT_MAX had type unsigned int.
However, lacking integer suffixes for types smaller than int, their type
should correspond to that of an object of type unsigned char (or short)
when used in an expression with objects of type int. In that case unsigned
char (short) are promoted to int (i.e. signed) so the type of UCHAR_MAX and
USHRT_MAX should also be int.
Where MIN/MAX constants implicitly have the correct type the suffix has
been removed.
While here, correct some comments.
Reviewed by: bde
Approved by: kib (mentor)
It was used mainly to discover and fix some 64-bit portability problems
before 64-bit arches were widely available.
Discussed with: bde
Approved by: kib (mentor)
be in {pmap_pinit, pmap_copy, pmap_release} at a time.
This reduces the rate of panics when running 'make index' from ~0.6/hour
to ~0.02/hour (p < 10^-30).
At a later date this locking will be removed, and for this reason, it is
wrapped in #ifdef HAMFISTED_LOCKING; this temporary hack is being put in
place with the intention of shipping somewhat-stable Xen bits in FreeBSD
8.2-RELEASE.
PR: kern/153672
MFC after: 3 days
mechanical change. This opens the door for using PV device drivers
under Xen HVM on i386, as well as more general harmonisation of i386
and amd64 Xen support in FreeBSD.
Reviewed by: cperciva
MFC after: 3 weeks
entire range where the page mapping request queue needs to be atomically
examined and modified.
Oddly, while this doesn't seem to affect the overall rate of panics
(running 'make index' on EC2 t1.micro instances, there are 0.6 +/- 0.1
panics per hour, both before and after this change), it eliminates
vm_fault from panic backtraces, leaving only backtraces going through
vmspace_fork.
When cleaning up a thread, reset its LDT to the default LDT.
Note: Casting the LDT pointer to an int and storing it in pc_currentldt is
wildly bogus, but is harmless since pc_currentldt is a write-only variable.
MFC after: 3 days
Use xen_update_descriptor to update the LDT rather than bcopy. Under Xen,
pages used for holding LDTs must be read-only, so we can't make the change
ourselves.
Ths obvious alternative of "remap the page read-write, make the change, then
map it read-only again" doesn't work since Xen won't allow an LDT page to be
remapped as R/W. An arguably better solution is used by NetBSD: They don't
modify LDTs in-place at all, but instead copy the entire LDT, modify the new
version, then atomically swap.
MFC after: 3 days
Synchronize reality with comment: The user_ldt_alloc function is supposed to
return with dt_lock held. Due to broken locking in i386/xen/pmap.c, we drop
dt_lock during the call to pmap_map_readonly and then pick it up again; this
can be removed once the Xen pmap locking is fixed.
MFC after: 3 days
Don't map physical to machine page numbers in pte_load_store, since it uses
PT_SET_VA (which takes a physical page number and converts it to a machine
page number).
MFC after: 3 days
Lock the vm page queue mutex around calls to pte_store. As with many other
uses of the vm page queue mutex in i386/xen/pmap.c, this is bogus and needs
to be replaced at some future date by a spin lock dedicated to protecting
the queue of pending xen page mapping hypervisor calls. (But for now, bogus
locking is better than a panic.)
MFC after: 3 days
The controller is commonly found on DM&P Vortex86 x86 SoC. The
driver supports all hardware features except flow control. The
flow control was intentionally disabled due to silicon bug.
DM&P Electronics, Inc. provided all necessary information including
sample board to write driver and answered many questions I had.
Many thanks for their support of FreeBSD.
H/W donated by: DM&P Electronics, Inc.
categories: Those which can't build with PAE because they attempt to cast
a pointer to a bus_addr_t (mostly scsi drivers); and those which can't be
built with XEN because they conflict with something in xen-os.h (e.g., in
cxgb there is a conflicting definition of test_and_clear_bit).
MFC after: 1 week
to PMAP_SET_VA; this fixes a mutex-not-held panic when a process
which called mlock(2) exits, and parallels a change made in
pmap_pte 10 months ago (svn r204160).
Note: The locking in this code is utterly broken. We should not
be using the VM page queue mutex to protect the queue of pending
Xen page mapping hypervisor calls. Even if it made sense to do
so, this commit and r204160 introduce LORs between the vm page
queue mutex and PMAP2mutex.
(However, a possible deadlock is better than a guaranteed panic,
and this change will hopefully make life easier for whoever fixes
the Xen pmap locking in the future.)
PR: kern/140313
MFC after: 3 days
the original amd64 and i386 headers with stubs.
Rename (AMD64|I386)_BUS_SPACE_* to X86_BUS_SPACE_* everywhere.
Reviewed by: imp (previous version), jhb
Approved by: kib (mentor)
function always returned the nominal frequency instead of current frequency
because we use RDTSC instruction to calculate difference in CPU ticks, which
is supposedly constant for the case. Now we support cpu_get_nominal_mhz()
for the case, instead. Note it should be just enough for most usage cases
because cpu_est_clockrate() is often times abused to find maximum frequency
of the processor.
mark user FPU context initialized, if current context is user context.
It was reversed in r215865, by inadequate change of this code fragment
to a call to fpuuserinited()/npxuserinited().
The issue is only relevant for in-kernel users of FPU.
Reported by: Jan Henrik Sylvester <me janh de>, Mike Tancsa <mike sentex net>
Tested by: Mike Tancsa
MFC after: 3 days
timecounter period from 2^32 ns (~4.3s) to 2^41 ns (~36m39s). Some time
sharing systems can skip clock interrupts for a few seconds when under
load (e.g., if we've recently used more than our fair share of CPU and
someone else wants a burst of CPU) and we were losing time in quanta of
2^32 ns due to timecounter wrapping.
Increasing the timecounter period up to 2^41 ns is definitely overkill,
but we still have microsecond timecounter precision, and anyone using
paravirtualized hardware when they need submicrosecond timing is crazy.
lock from pmap_extract_and_hold(), it didn't take into account that
pmap_pte_quick() sometimes requires the page queues lock to be held.
This change reimplements pmap_extract_and_hold() such that it no
longer uses pmap_pte_quick(), and thus never requires the page queues
lock.
For consistency, adopt the same idiom as used by the new
implementation of pmap_extract_and_hold() in pmap_extract() and
pmap_mincore(). It also happens to make these functions shorter.
Fix a style error in pmap_pte().
Reviewed by: kib@
while on i386 we have MAX_BPAGES=512. Implement this difference via
'#ifdef __i386__'.
With this commit, the i386 and amd64 busdma_machdep.c files become
identical; they will soon be replaced by a single file under sys/x86.
end of segments be aligned, not just the start of segments) in order to
allow Xen's blkfront driver to operate correctly.
PR: kern/152818
MFC after: 3 days
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
for CPU #0 weren't being properly reserved. Under VM pressure this would
cause problems when the dpcpu structures were overwritten by arbitrary
data; the most common symptom was a panic when netisr attempted to lock a
mutex.
For some reason the XEN code keeps track of the start of available memory
in the variables 'first', 'physfree', and 'init_first'; as far as I can
tell, we always have first == physfree == init_first * PAGE_SIZE. The
earlier commit adjusted 'first' (which, on !XEN, is the only variable
which tracks this value) but not the other two variables.
Exercise for reader: Eliminate two of these three variables.
functions, they are unused. Remove 'user' from npxgetuserregs()
etc. names.
For {npx,fpu}{get,set}regs(), always use pcb->pcb_user_save for FPU
context storage. This eliminates the need for ugly copying with
overwrite of the newly added and reserved fields in ucontext on i386
to satisfy alignment requirements for fpusave() and fpurstor().
pc98 version was copied from i386.
Suggested and reviewed by: bde
Tested by: pho (i386 and amd64)
MFC after: 1 week
updates were being queued by pmap_kremove, but the queue wasn't being
flushed; as a result, the updates didn't happen until *after* the call
to pmap_invalidate_range, and old entries could stick around in the TLB.
Adding a PT_UPDATES_FLUSH() call immediately before pmap_invalidate_range
ensures that after the invalidation the TLB will be repopulated with the
correct new entries.
Thanks to: kib, avg, alc
silently converts 'fld' to 'flds', without taking the actual variable
type into account (!), but clang's integrated assembler rightfully
complains about it.
Discussed with: cperciva
the TLB which don't correspond to ptes with PG_V set; prior to this commit
I'm sometimes getting the wrong data when pages are loaded into the buffer
cache (they're being loaded, but the missing TLB invalidation is causing
the wrong data to be visible).
_HYPERVISOR_multicall, and create a new HYPERVISOR_multicall function which
invokes _HYPERVISOR_multicall and checks that the individual hypercalls all
succeeded.
Flushing TLBs is required to ensure cache coherency according to the AMD64
architecture manual. Flushing caches is only required when changing from a
cacheable memory type (WB, WP, or WT) to an uncacheable type (WC, UC, or
UC-). Since this function is only used once per processor during startup,
there is no need to take any shortcuts.
- Leave PAT indices 0-3 at the default of WB, WT, UC-, and UC. Program 5 as
WP (from default WT) and 6 as WC (from default UC-). Leave 4 and 7 at the
default of WB and UC. This is to avoid transition from a cacheable memory
type to an uncacheable type to minimize possible cache incoherency. Since
we perform flushing caches and TLBs now, this change may not be necessary
any more but we do not want to take any chances.
- Remove Apple hardware specific quirks. With the above changes, it seems
this hack is no longer needed.
- Improve pmap_cache_bits() with an array to map PAT memory type to index.
This array is initialized early from pmap_init_pat(), so that we do not need
to handle special cases in the function any more. Now this function is
identical on both amd64 and i386.
Reviewed by: jhb
Tested by: RM (reuf_m at hotmail dot com)
Ryszard Czekaj (rychoo at freeshell dot net)
army.of.root (army dot of dot root at googlemail dot com)
MFC after: 3 days
Clean up the code by converting xpmap_ptom(VTOP(...)) to VTOM(...) and
converting xpmap_ptom(VM_PAGE_TO_PHYS(...)) to VM_PAGE_TO_MACH(...). In
a few places we take advantage of the fact that xpmap_ptom can commute with
setting PG_* flags.
This commit should have no net effect save to improve the readability of
this code.
pages. The pinning of NPGPTD pages is #if 0ed out in pmap_pinit (I'm
not quite sure why...) and this commit adds a corresponding #if 0 in
pmap_release to avoid unpinning those pages.
Some versions of Xen seem to silently ignore requests to unpin pages
which were never pinned in the first place, but some return an error
(causing FreeBSD to panic) prior to this commit.
These MSRs can be used to determine actual (average) performance as
compared to a maximum defined performance.
Availability of these MSRs is indicated by bit0 in CPUID.6.ECX on both
Intel and AMD processors.
MFC after: 5 days
It seems that this MSR has been available in a range of AMD processors
families for quite a while now.
Note1: not all AMD MSRs that are found in amd64 specialreg.h are also in
the i386 version.
Note2: perhaps some additional name component is needed to distinguish
AMD-specific MSRs.
MFC after: 5 days
xpmap_ptom(VM_PAGE_TO_PHYS(m)) == (pmap->pm_pdpt[i] & PG_FRAME)
for i = NPGPTD, since pmap->pm_pdpt[i] is only initialized for
0 <= i < NPGPTD.
This fixes an inevitable panic with XEN && PAE && INVARIANTS when
pmap_release is called (e.g., when /sbin/init is launched).
no noticeable change because we enable caches before we enter here for both
BSP and AP cases. Remove another pointless optimization for CR4.PGE bit
while I am here.
code but probably it only worked by chance because modifying CR4.PGE bit
causes invlidation of entire TLBs. Since these are very rare events, this
micro-optimization seems useless.
Reviewed by: jhb
The ports/Mk/bsd.port.mk uses sys/param.h to fetch osrel, and cannot
grok several constants with the prefix.
Reported and tested by: swell.k gmail com
MFC after: 1 week
Move logic of building ACPI headers for acpi_wakeup.c into better places,
remove intermediate makefile and shell script, and reduce diff between i386
and amd64.
contents of the ones that were not empty were stale and unused.
- Now that <machine/mutex.h> no longer exists, there is no need to allow it
to override various helper macros in <sys/mutex.h>.
- Rename various helper macros for low-level operations on mutexes to live
in the _mtx_* or __mtx_* namespaces. While here, change the names to more
closely match the real API functions they are backing.
- Drop support for including <sys/mutex.h> in assembly source files.
Suggested by: bde (1, 2)
- Register APIC enumerators at SI_SUB_TUNABLES - 1 instead of SI_SUB_CPU - 1.
- Probe CPUs at SI_SUB_TUNABLES - 1. This allows i386 to set a truly
accurate mp_maxid value rather than always setting it to MAXCPU - 1.
included in a kernel config. These stubs had existed previously so that
acpi.ko could always include the MADT parsing code and still link with a
kernel that did not include 'device apic'.
work properly with single-stepping in a kernel debugger. Specifically,
these routines have always disabled interrupts before increasing the nesting
count and restored the prior state of interrupts after decreasing the nesting
count to avoid problems with a nested interrupt not disabling interrupts
when acquiring a spin lock. However, trap interrupts for single-stepping
can still occur even when interrupts are disabled. Now the saved state of
interrupts is not saved in the thread until after interrupts have been
disabled and the nesting count has been increased. Similarly, the saved
state from the thread cannot be read once the nesting count has been
decreased to zero. To fix this, use temporary variables to store interrupt
state and shuffle it between the thread's MD area and the appropriate
registers.
In cooperation with: bde
MFC after: 1 month
This could lead to a division by zero if hardware is multi-core and/or
multi-threaded, but for some (quite unusual) reason FreeBSD sees only
one logical processor. This could happen, for example, if neither MADT
nor MP Table are presented by BIOS.
Also:
- assert in topo_probe_0x4 that BSP is accounted for
- neither cpu_cores nor cpu_logical should be zero after successful
probing, so either being zero is an indication of failed probing
Reported by: vwe, Dan Allen <danallen46@airwired.net>
Tested by: Dan Allen <danallen46@airwired.net>
MFC after: 3 days
- Use > 2^32 - 1 instead of >= when checking for memory regions above 4G.
- Skip SMAP entries > 4G on i386 rather than breaking out of the loop
since SMAP entries are not guaranteed to be in order.
- Remove 'i' and loop over 'rid' directly in the dump_avail[] case.
- Only check for 4G regions in the dump_avail[] case on i386 if PAE is
enabled since vm_paddr_t is 32-bit in the !PAE case.
Submitted by: alc
when routing interrupts instead of cpu_apic_ids[0] since cpu_apic_ids[]
is only populated for multiple-CPU machines. This also matches what the
code does when SMP is not enabled.
PR: bin/151616
Tested by: "Damian S. Kolodziejczyk" damkol | gmail
Submitted by: avg
MFC after: 1 week
o Add support for backend devices (e.g. blkback)
o Implement extensions to the Xen para-virtualized block API to allow
for larger and more outstanding I/Os.
o Import a completely rewritten block back driver with support for fronting
I/O to both raw devices and files.
o General cleanup and documentation of the XenBus and XenStore support code.
o Robustness and performance updates for the block front driver.
o Fixes to the netfront driver.
Sponsored by: Spectra Logic Corporation
sys/xen/xenbus/init.txt:
Deleted: This file explains the Linux method for XenBus device
enumeration and thus does not apply to FreeBSD's NewBus approach.
sys/xen/xenbus/xenbus_probe_backend.c:
Deleted: Linux version of backend XenBus service routines. It
was never ported to FreeBSD. See xenbusb.c, xenbusb_if.m,
xenbusb_front.c xenbusb_back.c for details of FreeBSD's XenBus
support.
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenbus/xenbus_xs.c:
sys/xen/xenbus/xenbus_comms.c:
sys/xen/xenbus/xenbus_comms.h:
sys/xen/xenstore/xenstorevar.h:
sys/xen/xenstore/xenstore.c:
Split XenStore into its own tree. XenBus is a software layer built
on top of XenStore. The old arrangement and the naming of some
structures and functions blurred these lines making it difficult to
discern what services are provided by which layer and at what times
these services are available (e.g. during system startup and shutdown).
sys/xen/xenbus/xenbus_client.c:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_probe.c:
sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
Split up XenBus code into methods available for use by client
drivers (xenbus.c) and code used by the XenBus "bus code" to
enumerate, attach, detach, and service bus drivers.
sys/xen/reboot.c:
sys/dev/xen/control/control.c:
Add a XenBus front driver for handling shutdown, reboot, suspend, and
resume events published in the XenStore. Move all PV suspend/reboot
support from reboot.c into this driver.
sys/xen/blkif.h:
New file from Xen vendor with macros and structures used by
a block back driver to service requests from a VM running a
different ABI (e.g. amd64 back with i386 front).
sys/conf/files:
Adjust kernel build spec for new XenBus/XenStore layout and added
Xen functionality.
sys/dev/xen/balloon/balloon.c:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/blkfront/blkfront.c:
sys/xen/xenbus/...
sys/xen/xenstore/...
o Rename XenStore APIs and structures from xenbus_* to xs_*.
o Adjust to use of M_XENBUS and M_XENSTORE malloc types for allocation
of objects returned by these APIs.
o Adjust for changes in the bus interface for Xen drivers.
sys/xen/xenbus/...
sys/xen/xenstore/...
Add Doxygen comments for these interfaces and the code that
implements them.
sys/dev/xen/blkback/blkback.c:
o Rewrite the Block Back driver to attach properly via newbus,
operate correctly in both PV and HVM mode regardless of domain
(e.g. can be in a DOM other than 0), and to deal with the latest
metadata available in XenStore for block devices.
o Allow users to specify a file as a backend to blkback, in addition
to character devices. Use the namei lookup of the backend path
to automatically configure, based on file type, the appropriate
backend method.
The current implementation is limited to a single outstanding I/O
at a time to file backed storage.
sys/dev/xen/blkback/blkback.c:
sys/xen/interface/io/blkif.h:
sys/xen/blkif.h:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
Extend the Xen blkif API: Negotiable request size and number of
requests.
This change extends the information recorded in the XenStore
allowing block front/back devices to negotiate for optimal I/O
parameters. This has been achieved without sacrificing backward
compatibility with drivers that are unaware of these protocol
enhancements. The extensions center around the connection protocol
which now includes these additions:
o The back-end device publishes its maximum supported values for,
request I/O size, the number of page segments that can be
associated with a request, the maximum number of requests that
can be concurrently active, and the maximum number of pages that
can be in the shared request ring. These values are published
before the back-end enters the XenbusStateInitWait state.
o The front-end waits for the back-end to enter either the InitWait
or Initialize state. At this point, the front end limits it's
own capabilities to the lesser of the values it finds published
by the backend, it's own maximums, or, should any back-end data
be missing in the store, the values supported by the original
protocol. It then initializes it's internal data structures
including allocation of the shared ring, publishes its maximum
capabilities to the XenStore and transitions to the Initialized
state.
o The back-end waits for the front-end to enter the Initalized
state. At this point, the back end limits it's own capabilities
to the lesser of the values it finds published by the frontend,
it's own maximums, or, should any front-end data be missing in
the store, the values supported by the original protocol. It
then initializes it's internal data structures, attaches to the
shared ring and transitions to the Connected state.
o The front-end waits for the back-end to enter the Connnected
state, transitions itself to the connected state, and can
commence I/O.
Although an updated front-end driver must be aware of the back-end's
InitWait state, the back-end has been coded such that it can
tolerate a front-end that skips this step and transitions directly
to the Initialized state without waiting for the back-end.
sys/xen/interface/io/blkif.h:
o Increase BLKIF_MAX_SEGMENTS_PER_REQUEST to 255. This is
the maximum number possible without changing the blkif
request header structure (nr_segs is a uint8_t).
o Add two new constants:
BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK, and
BLKIF_MAX_SEGMENTS_PER_SEGMENT_BLOCK. These respectively
indicate the number of segments that can fit in the first
ring-buffer entry of a request, and for each subsequent
(sg element only) ring-buffer entry associated with the
"header" ring-buffer entry of the request.
o Add the blkif_request_segment_t typedef for segment
elements.
o Add the BLKRING_GET_SG_REQUEST() macro which wraps the
RING_GET_REQUEST() macro and returns a properly cast
pointer to an array of blkif_request_segment_ts.
o Add the BLKIF_SEGS_TO_BLOCKS() macro which calculates the
number of ring entries that will be consumed by a blkif
request with the given number of segments.
sys/xen/blkif.h:
o Update for changes in interface/io/blkif.h macros.
o Update the BLKIF_MAX_RING_REQUESTS() macro to take the
ring size as an argument to allow this calculation on
multi-page rings.
o Add a companion macro to BLKIF_MAX_RING_REQUESTS(),
BLKIF_RING_PAGES(). This macro determines the number of
ring pages required in order to support a ring with the
supplied number of request blocks.
sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
o Negotiate with the other-end with the following limits:
Reqeust Size: MAXPHYS
Max Segments: (MAXPHYS/PAGE_SIZE) + 1
Max Requests: 256
Max Ring Pages: Sufficient to support Max Requests with
Max Segments.
o Dynamically allocate request pools and segemnts-per-request.
o Update ring allocation/attachment code to support a
multi-page shared ring.
o Update routines that access the shared ring to handle
multi-block requests.
sys/dev/xen/blkfront/blkfront.c:
o Track blkfront allocations in a blkfront driver specific
malloc pool.
o Strip out XenStore transaction retry logic in the
connection code. Transactions only need to be used when
the update to multiple XenStore nodes must be atomic.
That is not the case here.
o Fully disable blkif_resume() until it can be fixed
properly (it didn't work before this change).
o Destroy bus-dma objects during device instance tear-down.
o Properly handle backend devices with powef-of-2 sector
sizes larger than 512b.
sys/dev/xen/blkback/blkback.c:
Advertise support for and implement the BLKIF_OP_WRITE_BARRIER
and BLKIF_OP_FLUSH_DISKCACHE blkif opcodes using BIO_FLUSH and
the BIO_ORDERED attribute of bios.
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
Fix various bugs in blkfront.
o gnttab_alloc_grant_references() returns 0 for success and
non-zero for failure. The check for < 0 is a leftover
Linuxism.
o When we negotiate with blkback and have to reduce some of our
capabilities, print out the original and reduced capability before
changing the local capability. So the user now gets the correct
information.
o Fix blkif_restart_queue_callback() formatting. Make sure we hold
the mutex in that function before calling xb_startio().
o Fix a couple of KASSERT()s.
o Fix a check in the xb_remove_* macro to be a little more specific.
sys/xen/gnttab.h:
sys/xen/gnttab.c:
Define GNTTAB_LIST_END publicly as GRANT_REF_INVALID.
sys/dev/xen/netfront/netfront.c:
Use GRANT_REF_INVALID instead of driver private definitions of the
same constant.
sys/xen/gnttab.h:
sys/xen/gnttab.c:
Add the gnttab_end_foreign_access_references() API.
This API allows a client to batch the release of an array of grant
references, instead of coding a private for loop. The implementation
takes advantage of this batching to reduce lock overhead to one
acquisition and release per-batch instead of per-freed grant reference.
While here, reduce the duration the gnttab_list_lock is held during
gnttab_free_grant_references() operations. The search to find the
tail of the incoming free list does not rely on global state and so
can be performed without holding the lock.
sys/dev/xen/xenpci/evtchn.c:
sys/dev/xen/evtchn/evtchn.c:
sys/xen/xen_intr.h:
o Implement the bind_interdomain_evtchn_to_irqhandler API for HVM mode.
This allows an HVM domain to serve back end devices to other domains.
This API is already implemented for PV mode.
o Synchronize the API between HVM and PV.
sys/dev/xen/xenpci/xenpci.c:
o Scan the full region of CPUID space in which the Xen VMM interface
may be implemented. On systems using SuSE as a Dom0 where the
Viridian API is also exported, the VMM interface is above the region
we used to search.
o Pass through bus_alloc_resource() calls so that XenBus drivers
attaching on an HVM system can allocate unused physical address
space from the nexus. The block back driver makes use of this
facility.
sys/i386/xen/xen_machdep.c:
Use the correct type for accessing the statically mapped xenstore
metadata.
sys/xen/interface/hvm/params.h:
sys/xen/xenstore/xenstore.c:
Move hvm_get_parameter() to the correct global header file instead
of as a private method to the XenStore.
sys/xen/interface/io/protocols.h:
Sync with vendor.
sys/xeninterface/io/ring.h:
Add macro for calculating the number of ring pages needed for an N
deep ring.
To avoid duplication within the macros, create and use the new
__RING_HEADER_SIZE() macro. This macro calculates the size of the
ring book keeping struct (producer/consumer indexes, etc.) that
resides at the head of the ring.
Add the __RING_PAGES() macro which calculates the number of shared
ring pages required to support a ring with the given number of
requests.
These APIs are used to support the multi-page ring version of the
Xen block API.
sys/xeninterface/io/xenbus.h:
Add Comments.
sys/xen/xenbus/...
o Refactor the FreeBSD XenBus support code to allow for both front and
backend device attachments.
o Make use of new config_intr_hook capabilities to allow front and back
devices to be probed/attached in parallel.
o Fix bugs in probe/attach state machine that could cause the system to
hang when confronted with a failure either in the local domain or in
a remote domain to which one of our driver instances is attaching.
o Publish all required state to the XenStore on device detach and
failure. The majority of the missing functionality was for serving
as a back end since the typical "hot-plug" scripts in Dom0 don't
handle the case of cleaning up for a "service domain" that is not
itself.
o Add dynamic sysctl nodes exposing the generic ivars of
XenBus devices.
o Add doxygen style comments to the majority of the code.
o Cleanup types, formatting, etc.
sys/xen/xenbus/xenbusb.c:
Common code used by both front and back XenBus busses.
sys/xen/xenbus/xenbusb_if.m:
Method definitions for a XenBus bus.
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusb_back.c:
XenBus bus specialization for front and back devices.
MFC after: 1 month
kernel of exactly the same __FreeBSD_version as the headers module was
compiled against.
Mark our in-tree ABI emulators with DECLARE_MODULE_TIED. The modules
use kernel interfaces that the Release Engineering Team feel are not
stable enough to guarantee they will not change during the life cycle
of a STABLE branch. In particular, the layout of struct sysentvec is
declared to be not part of the STABLE KBI.
Discussed with: bz, rwatson
Approved by: re (bz, kensmith)
MFC after: 2 weeks
pmap_kextract()) before pmap_bootstrap() is called.
Document the set of pmap functions that may be called before
pmap_bootstrap() is called.
Tested by: bde@
Reviewed by: kib@
Discussed with: jhb@
MFC after: 6 weeks
This patch is significantly based on previous work by jkim.
List of changes:
- added comments that describe topology uniformity assumption
- added reference to Intel Processor Topology Enumeration article
- documented a few global variables that describe topology
- retired weirdly set and used logical_cpus variable
- changed fallback code for mp_ncpus > 0 case, so that CPUs are treated
as being different packages rather than cores in a single package
- moved AMD-specific code to topo_probe_amd [jkim]
- in topo_probe_0x4() follow Intel-prescribed procedure of deriving SMT
and core masks and match APIC IDs against those masks [started by
jkim]
- in topo_probe_0x4() drop code for double-checking topology parameters
by looking at L1 cache properties [jkim]
- in topo_probe_0xb() add fallback path to topo_probe_0x4() as
prescribed by Intel [jkim]
Still to do:
- prepare for upcoming AMD CPUs by using new mechanism of uniform
topology description [pointed by jkim]
- probe cache topology in addition to CPU topology and probably use that
for scheduler affinity topology; e.g. Core2 Duo and Athlon II X2 have
the same CPU topology, but Athlon cores do not share L2 cache while
Core2's do (no L3 cache in both cases)
- think of supporting non-uniform topologies if they are ever
implemented for platforms in question
- think how to better described old HTT vs new HTT distinction, HTT vs
SMT can be confusing as SMT is a generic term
- more robust code for marking CPUs as "logical" and/or "hyperthreaded",
use HTT mask instead of modulo operation
- correct support for halting logical and/or hyperthreaded CPUs, let
scheduler know that it shouldn't schedule any threads on those CPUs
PR: kern/145385 (related)
In collaboration with: jkim
Tested by: Sergey Kandaurov <pluknet@gmail.com>,
Jeremy Chadwick <freebsd@jdc.parodius.com>,
Chip Camden <sterling@camdensoftware.com>,
Steve Wills <steve@mouf.net>,
Olivier Smedts <olivier@gid0.org>,
Florian Smeets <flo@smeets.im>
MFC after: 1 month
The check for alignment should be made against the physical address and not
the virtual address that maps it.
Sponsored by: NetApp
Submitted by: Will McGovern (will at netapp dot com)
Reviewed by: mjacob, jhb
- Check for SMAP data from the loader first. If it exists, don't bother
doing any VM86 calls at all. This will be more friendly for non-BIOS
boot environments such as EFI, etc.
- Move the base memory setup into a new basemem_setup() routine instead
of duplicating it.
- Simplify the XEN case by removing all of the VM86/SMAP parsing code rather
than just jumping over it.
- Adjust some comments to better explain the code flow.
MFC after: 2 weeks
The main goal of this is to generate timer interrupts only when there is
some work to do. When CPU is busy interrupts are generating at full rate
of hz + stathz to fullfill scheduler and timekeeping requirements. But
when CPU is idle, only minimum set of interrupts (down to 8 interrupts per
second per CPU now), needed to handle scheduled callouts is executed.
This allows significantly increase idle CPU sleep time, increasing effect
of static power-saving technologies. Also it should reduce host CPU load
on virtualized systems, when guest system is idle.
There is set of tunables, also available as writable sysctls, allowing to
control wanted event timer subsystem behavior:
kern.eventtimer.timer - allows to choose event timer hardware to use.
On x86 there is up to 4 different kinds of timers. Depending on whether
chosen timer is per-CPU, behavior of other options slightly differs.
kern.eventtimer.periodic - allows to choose periodic and one-shot
operation mode. In periodic mode, current timer hardware taken as the only
source of time for time events. This mode is quite alike to previous kernel
behavior. One-shot mode instead uses currently selected time counter
hardware to schedule all needed events one by one and program timer to
generate interrupt exactly in specified time. Default value depends of
chosen timer capabilities, but one-shot mode is preferred, until other is
forced by user or hardware.
kern.eventtimer.singlemul - in periodic mode specifies how much times
higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 2 and 4, but could be reduced to 1
if extra interrupts are unwanted.
kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
independently of whether they busy or not. By default this options is
disabled. If chosen timer is per-CPU and runs in periodic mode, this option
has no effect - all interrupts are generating.
As soon as this patch modifies cpu_idle() on some platforms, I have also
refactored one on x86. Now it makes use of MONITOR/MWAIT instrunctions
(if supported) under high sleep/wakeup rate, as fast alternative to other
methods. It allows SMP scheduler to wake up sleeping CPUs much faster
without using IPI, significantly increasing performance on some highly
task-switching loads.
Tested by: many (on i386, amd64, sparc64 and powerc)
H/W donated by: Gheorghe Ardelean
Sponsored by: iXsystems, Inc.
This reflects actual type used to store and compare child device orders.
Change is mostly done via a Coccinelle (soon to be devel/coccinelle)
semantic patch.
Verified by LINT+modules kernel builds.
Followup to: r212213
MFC after: 10 days
Makefiles or *.mk files, use ${CC:T:Mfoo} instead, so only the basename
of the compiler command (excluding any arguments) is considered.
This allows you to use, for example, CC="/nondefault/path/clang -xxx",
and still have the various tests in bsd.*.mk identify your compiler as
clang correctly.
ICC if cases were also changed.
Submitted by: Dimitry Andric <dimitry at andric.com>
In particular, provide pagesize and pagesizes array, the canary value
for SSP use, number of host CPUs and osreldate.
Tested by: marius (sparc64)
MFC after: 1 month
As long as interrupts are disabled and there is not explicit call to
sched_add() there can't be any preemption there, thus the calls may be
consistent.
Reported by: kib, jhb
are served via an interrupt gate.
However, that doesn't explicitly prevent preemption and thread
migration thus scheduler pinning may be necessary in some handlers.
Fix that.
Tested by: gianni
MFC after: 1 month
While there, also fix some places assuming cpu type is 'int' while
u_int is really meant.
Note: this will also fix some possible races in per-cpu data accessings
to be addressed in further commits.
In collabouration with: Yahoo! Incorporated (via sbruno and peter)
Tested by: gianni
MFC after: 1 month
IPI to a specific CPU by its cpuid. Replace calls to ipi_selected() that
constructed a mask for a single CPU with calls to ipi_cpu() instead. This
will matter more in the future when we transition from cpumask_t to
cpuset_t for CPU masks in which case building a CPU mask is more expensive.
Submitted by: peter, sbruno
Reviewed by: rookie
Obtained from: Yahoo! (x86)
MFC after: 1 month
VM86 calls instead of the real mode emulator as a backend. VM86 has been
proven reliable for very long time and it is actually few times faster than
emulation. Increase maximum number of page table entries per VM86 context
from 3 to 8 pages. It was (ridiculously) low and insufficient for new VM86
backend, which shares one context globally. Slighly rearrange and clean up
the emulator backend to accommodate new code. The only visible change here
is stack size, which is decreased from 64K to 4K bytes to sync. with VM86.
Actually, it seems there is no need for big stack in real mode.
MFC after: 1 month
Xeon 5500/5600 series:
- Utilize IA32_TEMPERATURE_TARGET, a.k.a. Tj(target) in place
of Tj(max) when a sane value is available, as documented
in Intel whitepaper "CPU Monitoring With DTS/PECI"; (By sane
value we mean 70C - 100C for now);
- Print the probe results when booting verbose;
- Replace cpu_mask with cpu_stepping;
- Use CPUID_* macros instead of rolling our own.
Approved by: rpaulo
MFC after: 1 month
from the inline assembly. This allows the compiler to cache invocations of
curthread since it's value does not change within a thread context.
Submitted by: zec (i386)
MFC after: 1 week
Fix another fallout from r208833. savectx() is used to save CPU context
for crash dump (dumppcb) and kdb (stoppcbs). For both cases, we cannot
have a valid pointer in pcb_save. This should restore the previous
behaviour.
zones for each malloc bucket size. The purpose is to isolate
different malloc types into hash classes, so that any buffer overruns
or use-after-free will usually only affect memory from malloc types in
that hash class. This is purely a debugging tool; by varying the hash
function and tracking which hash class was corrupted, the intersection
of the hash classes from each instance will point to a single malloc
type that is being misused. At this point inspection or memguard(9)
can be used to catch the offending code.
Add MALLOC_DEBUG_MAXZONES=8 to -current GENERIC configuration files.
The suggestion to have this on by default came from Kostik Belousov on
-arch.
This code is based on work by Ron Steinke at Isilon Systems.
Reviewed by: -arch (mostly silence)
Reviewed by: zml
Approved by: zml (mentor)
now it uses a very dumb first-touch allocation policy. This will change in
the future.
- Each architecture indicates the maximum number of supported memory domains
via a new VM_NDOMAIN parameter in <machine/vmparam.h>.
- Each cpu now has a PCPU_GET(domain) member to indicate the memory domain
a CPU belongs to. Domain values are dense and numbered from 0.
- When a platform supports multiple domains, the default freelist
(VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain.
The MD code is required to populate an array of mem_affinity structures.
Each entry in the array defines a range of memory (start and end) and a
domain for the range. Multiple entries may be present for a single
domain. The list is terminated by an entry where all fields are zero.
This array of structures is used to split up phys_avail[] regions that
fall in VM_FREELIST_DEFAULT into per-domain freelists.
- Each memory domain has a separate lookup-array of freelists that is
used when fulfulling a physical memory allocation. Right now the
per-domain freelists are listed in a round-robin order for each domain.
In the future a table such as the ACPI SLIT table may be used to order
the per-domain lookup lists based on the penalty for each memory domain
relative to a specific domain. The lookup lists may be examined via a
new vm.phys.lookup_lists sysctl.
- The first-touch policy is implemented by using PCPU_GET(domain) to
pick a lookup list when allocating memory.
Reviewed by: alc
systems with PnP/ACPI not reporting i8254 timer. In some cases it can be
fatal, as i8254 can be the only available time counter hardware. From other
side we are now heavily depend on i8254 timer and till the last time it's
init/usage was completely hardcoded. So this change just restores previous
behavior in more regular fashion.
Specifically, teach pmap_qenter() to recognize the case when it is being
asked to replace a mapping with the very same mapping and not generate
a shootdown. Unfortunately, the buffer cache commonly passes an entire
buffer to pmap_qenter() when only a subset of the mappings are changing.
For the extension of buffers in allocbuf() this was resulting in
unnecessary shootdowns. The addition of new pages to the end of the
buffer need not and did not trigger a shootdown, but overwriting the
initial mappings with the very same mappings was seen as a change that
necessitated a shootdown. With this change, that is no longer so.
For a "buildworld" on amd64, this change eliminates 14-15% of the
pmap_invalidate_range() shootdowns, and about 4% of the overall
shootdowns.
MFC after: 3 weeks
- change the type of pm_active to cpumask_t, which it is;
- in pmap_remove_pages(), compare with PCPU(curpmap), instead of
dereferencing the long chain of pointers [1].
For amd64 pmap, remove the unneeded checks for validity of curpmap
in pmap_activate(), since curpmap should be always valid after
r209789.
Submitted by: alc [1]
Reviewed by: alc
MFC after: 3 weeks
It has more features than acpi_aiboost(4) and it will eventually replace
acpi_aiboost(4).
Submitted by: Constantine A. Murenin <cnst at FreeBSD.org>
Reviewed by: freebsd-acpi, imp
MFC after: 1 month
ABI specifies the DF should be zero, and newer compilers do not clear
DF before using DF-sensitive instructions.
The DF clearing for signal handlers was done some time ago.
MFC after: 1 week
get_fpcontext(), and npxsetuserregs() for set_fpcontext). Also,
note that usercontext is not initialized anymore in fpstate_drop().
Systematically replace references to npxgetregs() and npxsetregs()
by npxgetuserregs() and npxsetuserregs() in comments.
Noted by: bde
removal, MFi386 r209198:
Use critical sections instead of disabling local interrupts to ensure
the consistency between PCPU fpcurthread and the state of FPU.
Reviewed by: bde
Tested by: pho
believed that all 486-class CPUs FreeBSD is capable to run on, either
have no FPU and cannot use external coprocessor, or have FPU on the
package and can use #MF.
Reviewed by: bde
Tested by: pho (previous version)
FPU registers for copying. Remove the switch table and jumps from
bcopy/bzero/... to the actual implementation.
As a side-effect, i486-optimized bzero is removed.
Reviewed by: bde
Tested by: pho (previous version)
writing event timer drivers, for choosing best possible drivers by machine
independent code and for operating them to supply kernel with hardclock(),
statclock() and profclock() events in unified fashion on various hardware.
Infrastructure provides support for both per-CPU (independent for every CPU
core) and global timers in periodic and one-shot modes. MI management code
at this moment uses only periodic mode, but one-shot mode use planned for
later, as part of tickless kernel project.
For this moment infrastructure used on i386 and amd64 architectures. Other
archs are welcome to follow, while their current operation should not be
affected.
This patch updates existing drivers (i8254, RTC and LAPIC) for the new
order, and adds event timers support into the HPET driver. These drivers
have different capabilities:
LAPIC - per-CPU timer, supports periodic and one-shot operation, may
freeze in C3 state, calibrated on first use, so may be not exactly precise.
HPET - depending on hardware can work as per-CPU or global, supports
periodic and one-shot operation, usually provides several event timers.
i8254 - global, limited to periodic mode, because same hardware used also
as time counter.
RTC - global, supports only periodic mode, set of frequencies in Hz
limited by powers of 2.
Depending on hardware capabilities, drivers preferred in following orders,
either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC.
User may explicitly specify wanted timers via loader tunables or sysctls:
kern.eventtimer.timer1 and kern.eventtimer.timer2.
If requested driver is unavailable or unoperational, system will try to
replace it. If no more timers available or "NONE" specified for second,
system will operate using only one timer, multiplying it's frequency by few
times and uing respective dividers to honor hz, stathz and profhz values,
set during initial setup.
This information can be very valuable for CPU sleep-time (and respectively
idle power consumption) optimization.
Add counters for timer-related IPIs.
Reviewed by: jhb@ (previous version)
allow pmap_enter() to be performed on an unmanaged page that doesn't have
VPO_BUSY set. Having VPO_BUSY set really only matters for managed pages.
(See, for example, pmap_remove_write().)
in Linux emulation layer. Linux seems to only require that pos is
page-aligned, but otherwise ignores it. Default FreeBSD mmap parameter
checking is too strict to allow some Linux binaries to run. tsMuxeR is
one example of such a binary.
Discussed with: jhb
MFC after: 1 week
PG_REFERENCED changes in vm_pageout_object_deactivate_pages().
Simplify this function's inner loop using TAILQ_FOREACH(), and shorten
some of its overly long lines. Update a stale comment.
Assert that PG_REFERENCED may be cleared only if the object containing
the page is locked. Add a comment documenting this.
Assert that a caller to vm_page_requeue() holds the page queues lock,
and assert that the page is on a page queue.
Push down the page queues lock into pmap_ts_referenced() and
pmap_page_exists_quick(). (As of now, there are no longer any pmap
functions that expect to be called with the page queues lock held.)
Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever
be passed an unmanaged page. Assert this rather than returning "0"
and "FALSE" respectively.
ARM:
Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH().
Push down the page queues lock inside of pmap_clearbit(), simplifying
pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write().
Additionally, this allows for avoiding the acquisition of the page
queues lock in some cases.
PowerPC/AIM:
moea*_page_exits_quick() and moea*_page_wired_mappings() will never be
called before pmap initialization is complete. Therefore, the check
for moea_initialized can be eliminated.
Push down the page queues lock inside of moea*_clear_bit(),
simplifying moea*_clear_modify() and moea*_clear_reference().
The last parameter to moea*_clear_bit() is never used. Eliminate it.
PowerPC/BookE:
Simplify mmu_booke_page_exists_quick()'s control flow.
Reviewed by: kib@
the interrupt followed by a brief delay if it is not currently masked
before moving the interrupt.
- Move the icu_lock out of ioapic_program_intpin() and into callers. This
closes a race where ioapic_program_intpin() could use a stale value of
the masked state to compute the masked bit in the register.
Reviewed by: mav
MFC after: 2 weeks
FPU/SSE hardware. Caller should provide a save area that is chained
into the stack of the areas; pcb save_area for usermode FPU state is
on top. The pcb now contains a pointer to the current FPU saved area,
used during FPUDNA handling and context switches. There is also a
facility to allow the kernel thread to use pcb save_area.
Change the dreaded warnings "npxdna in kernel mode!" into the panics
when FPU usage is not registered.
KPI discussed with: fabient
Tested by: pho, fabient
Hardware provided by: Sentex Communications
MFC after: 1 month
fields that is always included in PCPU_MD_FIELDS. The macro is empty for
non-XEN kernels. This avoids duplicating non-XEN per-CPU fields in two
places. While here, remove several unused fields from the XEN-specific
structure.
Reviewed by: kmacy, gibbs
MFC after: 1 month
The remaining, unmerged portions of r175404
Retire PMAP_DIAGNOSTIC. Any useful diagnostics that were conditionally
compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel
option DIAGNOSTIC still disables inlining of certain pmap functions.)
Eliminate dead code from pmap_enter(). This code implemented an assertion.
On i386, an equivalent check is already implemented. However, on amd64,
a small change is required to implement an equivalent check.
Eliminate \n from a nearby panic string.
Use KASSERT() to reimplement pmap_copy()'s two assertions.
Merge portions of r177659
To date, we have assumed that the TLB will only set the PG_M bit in a
PTE if that PTE has the PG_RW bit set. However, this assumption does
not hold on recent processors from Intel. For example, consider a PTE
that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE
is cached in the TLB and later the PG_RW bit is cleared in the PTE,
but the corresponding TLB entry is not (yet) invalidated.
Historically, upon a write access using this (stale) TLB entry, the
TLB would observe that the PG_RW bit had been cleared and initiate a
page fault, aborting the setting of the PG_M bit in the PTE. Now,
however, P4- and Core2-family processors will set the PG_M bit before
observing that the PG_RW bit is clear and initiating a page fault. In
other words, the write does not occur but the PG_M bit is still set.
The real impact of this difference is not that great. Specifically,
we should no longer assert that any PTE with the PG_M bit set must
also have the PG_RW bit set, and we should ignore the state of the
PG_M bit unless the PG_RW bit is set.
r208609
Defer freeing any page table pages in pmap_remove_all() until after the
page queues lock is released. This may reduce the amount of time that the
page queues lock is held by pmap_remove_all().
r208645
When I pushed down the page queues lock into pmap_is_modified(), I created
an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls
vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified()
could return FALSE without acquiring the page queues lock because the page
is not (currently) writeable, and the caller to pmap_is_modified() might
believe that the page's dirty field is clear because it has not seen the
effect of the vm_page_dirty() call.
When I pushed down the page queues lock into pmap_is_modified(), I
overlooked one place where this ordering dependence is violated:
pmap_enter(). In a rare situation pmap_enter() can be called to replace a
dirty mapping to one page with a mapping to another page. (I say rare
because replacements generally occur as a result of a copy-on-write fault,
and so the old page is not dirty.) This change delays clearing PG_WRITEABLE
until after vm_page_dirty() has been called.
Fixing the ordering dependency also makes it easy to introduce a small
optimization: When pmap_enter() used to replace a mapping to one page with a
mapping to another page, it freed the pv entry for the first mapping and
later called the pv entry allocator for the new mapping. Now, pmap_enter()
attempts to recycle the old pv entry, saving two calls to the pv entry
allocator.
There is no point in setting PG_WRITEABLE on unmanaged pages, so don't.
Update a comment to reflect this.
Tidy up the variable declarations at the start of pmap_enter().
an ordering dependence: A pmap operation that clears PG_WRITEABLE and calls
vm_page_dirty() must perform the call first. Otherwise, pmap_is_modified()
could return FALSE without acquiring the page queues lock because the page
is not (currently) writeable, and the caller to pmap_is_modified() might
believe that the page's dirty field is clear because it has not seen the
effect of the vm_page_dirty() call.
When I pushed down the page queues lock into pmap_is_modified(), I
overlooked one place where this ordering dependence is violated:
pmap_enter(). In a rare situation pmap_enter() can be called to replace a
dirty mapping to one page with a mapping to another page. (I say rare
because replacements generally occur as a result of a copy-on-write fault,
and so the old page is not dirty.) This change delays clearing PG_WRITEABLE
until after vm_page_dirty() has been called.
Fixing the ordering dependency also makes it easy to introduce a small
optimization: When pmap_enter() used to replace a mapping to one page with a
mapping to another page, it freed the pv entry for the first mapping and
later called the pv entry allocator for the new mapping. Now, pmap_enter()
attempts to recycle the old pv entry, saving two calls to the pv entry
allocator.
There is no point in setting PG_WRITEABLE on unmanaged pages, so don't.
Update a comment to reflect this.
Tidy up the variable declarations at the start of pmap_enter().
pmap_is_referenced(). Eliminate the corresponding page queues lock
acquisitions from vm_map_pmap_enter() and mincore(), respectively. In
mincore(), this allows some additional cases to complete without ever
acquiring the page queues lock.
Assert that the page is managed in pmap_is_referenced().
On powerpc/aim, push down the page queues lock acquisition from
moea*_is_modified() and moea*_is_referenced() into moea*_query_bit().
Again, this will allow some additional cases to complete without ever
acquiring the page queues lock.
Reorder a few statements in vm_page_dontneed() so that a race can't lead
to an old reference persisting. This scenario is described in detail by a
comment.
Correct a spelling error in vm_page_dontneed().
Assert that the object is locked in vm_page_clear_dirty(), and restrict the
page queues lock assertion to just those cases in which the page is
currently writeable.
Add object locking to vnode_pager_generic_putpages(). This was the one
and only place where vm_page_clear_dirty() was being called without the
object being locked.
Eliminate an unnecessary vm_page_lock() around vnode_pager_setsize()'s call
to vm_page_clear_dirty().
Change vnode_pager_generic_putpages() to the modern-style of function
definition. Also, change the name of one of the parameters to follow
virtual memory system naming conventions.
Reviewed by: kib
APIC interrupt that fires when a threshold of corrected machine check
events is reached. CMCI also includes a count of events when reporting
corrected errors in the bank's status register. Note that individual
banks may or may not support CMCI. If they do, each bank includes its own
threshold register that determines when the interrupt fires. Currently
the code uses a very simple strategy where it doubles the threshold on
each interrupt until it succeeds in throttling the interrupt to occur
only once a minute (this interval can be tuned via sysctl). The threshold
is also adjusted on each hourly poll which will lower the threshold once
events stop occurring.
Tested by: Sailaja Bangaru sbappana at yahoo com
MFC after: 1 month
independent code. Move this code into mincore(), and eliminate the
page queues lock from pmap_mincore().
Push down the page queues lock into pmap_clear_modify(),
pmap_clear_reference(), and pmap_is_modified(). Assert that these
functions are never passed an unmanaged page.
Eliminate an inaccurate comment from powerpc/powerpc/mmu_if.m:
Contrary to what the comment says, pmap_mincore() is not simply an
optimization. Without a complete pmap_mincore() implementation,
mincore() cannot return either MINCORE_MODIFIED or MINCORE_REFERENCED
because only the pmap can provide this information.
Eliminate the page queues lock from vfs_setdirty_locked_object(),
vm_pageout_clean(), vm_object_page_collect_flush(), and
vm_object_page_clean(). Generally speaking, these are all accesses
to the page's dirty field, which are synchronized by the containing
vm object's lock.
Reduce the scope of the page queues lock in vm_object_madvise() and
vm_page_dontneed().
Reviewed by: kib (an earlier version)
arbitrary frequencies into hardclock(), statclock() and profclock() calls.
Same code with minor variations duplicated several times over the tree for
different timer drivers and architectures.
- Switch all x86 archs to new functions, simplifying the code and removing
extra logic from timer drivers. Other archs are also welcome.
Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
usermode into struct syscall_args. The structure is machine-depended
(this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
from the syscall. It is a generalization of
cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
return value.
sv_syscallnames - the table of syscall names.
Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().
The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.
Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().
Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively. The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.
The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.
Reviewed by: jhb, marcel, marius, nwhitehorn, stas
Tested by: marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
stas (mips)
MFC after: 1 month
here, make the style of assertion used by pmap_enter() consistent
across all architectures.
On entry to pmap_remove_write(), assert that the page is neither
unmanaged nor fictitious, since we cannot remove write access to
either kind of page.
With the push down of the page queues lock, pmap_remove_write() cannot
condition its behavior on the state of the PG_WRITEABLE flag if the
page is busy. Assert that the object containing the page is locked.
This allows us to know that the page will neither become busy nor will
PG_WRITEABLE be set on it while pmap_remove_write() is running.
Correct a long-standing bug in vm_page_cowsetup(). We cannot possibly
do copy-on-write-based zero-copy transmit on unmanaged or fictitious
pages, so don't even try. Previously, the call to pmap_remove_write()
would have failed silently.
On a soekris Net5501, if you do a watchdog -t 16, followed by a watchdog
-t 0 to disable the watchdog, and then after some time (16s) re-enable
the watchdog the box reboots immediatly. This prevents also to stop and
restart watchdogd(8).
This is because when you stop the watchdog, the timer is not stoped,
only the hard reset is disabled. So when the timer has elapsed, the C2
event of the timer is set.
But when the hard reset is re-enabled, the event is not cleared and the
box reboots.
The attached patch stops and resets the counter when the watchdog is
disabled and do not disable the hard reset of the timer (if the timer
has elapsed it's too late).
Submitted by: Patrick Lamaizière
vm_page_try_to_free(). Consequently, push down the page queues lock into
pmap_enter_quick(), pmap_page_wired_mapped(), pmap_remove_all(), and
pmap_remove_write().
Push down the page queues lock into Xen's pmap_page_is_mapped(). (I
overlooked the Xen pmap in r207702.)
Switch to a per-processor counter for the total number of pages cached.
pmap_page_is_mapped() in preparation for removing page queues locking
around calls to vm_page_free(). Setting aside the assertion that calls
pmap_page_is_mapped(), vm_page_free_toq() now acquires and holds the page
queues lock just long enough to actually add or remove the page from the
paging queues.
Update vm_page_unhold() to reflect the above change.
architecture from page queue lock to a hashed array of page locks
(based on a patch by Jeff Roberson), I've implemented page lock
support in the MI code and have only moved vm_page's hold_count
out from under page queue mutex to page lock. This changes
pmap_extract_and_hold on all pmaps.
Supported by: Bitgravity Inc.
Discussed with: alc, jeffr, and kib
In the end, it does help fixing /dev/io usage from multithreaded
processes.
- On i386 and amd64 the old behaviour is kept but multithreaded
processes must use the new interface in order to work well.
- Support for the other architectures is greatly improved, where
necessary, by the necessity to define very small things now.
Manpage update will happen shortly.
Sponsored by: Sandvine Incorporated
PR: threads/116181
Reviewed by: emaste, marcel
MFC after: 3 weeks
Clearing a page table entry's accessed bit (PG_A) and setting the
page's PG_REFERENCED flag in pmap_protect() can't really be justified,
so don't do it.
page's PG_REFERENCED flag in pmap_protect() can't really be justified.
In contrast to pmap_remove() or pmap_remove_all(), the mapping is not
being destroyed, so the notion that the page was accessed is not lost.
Moreover, clearing the page table entry's accessed bit and setting the
page's PG_REFERENCED flag can throw off the page daemon's activity
count calculation. Finally, in my tests, I found that 15% of the
atomic memory operations being performed by pmap_protect() were only
to clear PG_A, and not change protection. This could, by itself, be
fixed, but I don't see the point given the above argument.
Remove a comment from pmap_protect_pde() that is no longer meaningful
after the above change.
pmap_ts_referenced() is not always appropriate for checking whether or
not pages have been referenced because it clears any reference bits
that it encounters. For example, in mincore(), clearing the reference
bits has two negative consequences. First, it throws off the activity
count calculations performed by the page daemon. Specifically, a page
on which mincore() has called pmap_ts_referenced() looks less active
to the page daemon than it should. Consequently, the page could be
deactivated prematurely by the page daemon. Arguably, this problem
could be fixed by having mincore() duplicate the activity count
calculation on the page. However, there is a second problem for which
that is not a solution. In order to clear a reference on a 4KB page,
it may be necessary to demote a 2/4MB page mapping. Thus, a mincore()
by one process can have the side effect of demoting a superpage
mapping within another process!
This driver was written by Alexander Pohoyda and greatly enhanced
by Nikolay Denev. I don't have these hardwares but this driver was
tested by Nikolay Denev and xclin.
Because SiS didn't release data sheet for this controller, programming
information came from Linux driver and OpenSolaris. Unlike other open
source driver for SiS190/191, sge(4) takes full advantage of TX/RX
checksum offloading and does not require additional copy operation in
RX handler.
The controller seems to have advanced offloading features like VLAN
hardware tag insertion/stripping, TCP segmentation offload(TSO) as
well as jumbo frame support but these features are not available
yet. Special thanks to xclin <xclin<> cs dot nctu dot edu dot tw>
who sent fix for receiving VLAN oversized frames.
about inacessible or wrong mcontext, and for dreaded "kernel trap with
interrupts disabled" situation. The later is changed when trap is
generated from user mode (shall never be ?).
Normalize the messages to include both pid and thread name.
MFC after: 1 week
domain clock, 8 programmable PMC.
- Westmere based CPU (Xeon 5600, Corei7 980X) support.
- New man pages with events list for core and uncore.
- Updated Corei7 events with Intel 253669-033US December 2009 doc.
There is some removed events in the documentation, they have been
kept in the code but documented in the man page as obsolete.
- Offcore response events can be setup with rsp token.
Sponsored by: NETASQ
A nice thing about POSIX 2008 is that it finally standardizes a way to
obtain file access/modification/change times in sub-second precision,
namely using struct timespec, which we already have for a very long
time. Unfortunately POSIX uses different names.
This commit adds compatibility macros, so existing code should still
build properly. Also change all source code in the kernel to work
without any of the compatibility macros. This makes it all a less
ambiguous.
I am also renaming st_birthtime to st_birthtim, even though it was a
local extension anyway. It seems Cygwin also has a st_birthtim.
