Right now, userspace (fast) gettimeofday(2) on x86 only works for
RDTSC. For older machines, like Core2, where RDTSC is not C2/C3
invariant, and which fall to HPET hardware, this means that the call
has both the penalty of the syscall and of the uncached hw behind the
QPI or PCIe connection to the sought bridge. Nothing can me done
against the access latency, but the syscall overhead can be removed.
System already provides mappable /dev/hpetX devices, which gives
straight access to the HPET registers page.
Add yet another algorithm to the x86 'vdso' timehands. Libc is updated
to handle both RDTSC and HPET. For HPET, the index of the hpet device
to mmap is passed from kernel to userspace, index might be changed and
libc invalidates its mapping as needed.
Remove cpu_fill_vdso_timehands() KPI, instead require that
timecounters which can be used from userspace, to provide
tc_fill_vdso_timehands{,32}() methods. Merge i386 and amd64
libc/<arch>/sys/__vdso_gettc.c into one source file in the new
libc/x86/sys location. __vdso_gettc() internal interface is changed
to move timecounter algorithm detection into the MD code.
Measurements show that RDTSC even with the syscall overhead is faster
than userspace HPET access. But still, userspace HPET is three-four
times faster than syscall HPET on several Core2 and SandyBridge
machines.
Tested by: Howard Su <howard0su@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D7473
time, by, by default disallow writes to the mmaped HPET pages.
Intent is to allow userspace to use HPET as fast (i.e. no-syscall)
timecounter for gettimeofday(2). Unfortunately, the permission model
does not make it possible to safely unhide /dev/hpet in the jails even
if default mode is set to 0444, because untrusted jailed root may
change device permissions to writeable.
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
SRB status is set to 0x20 by the hypervisor, if the specified LUN is
unaccessible, and even worse the INQUIRY response will not be set by
the hypervisor at all under this situation. Additionally, SRB status
is 0x20 too, for TUR on an unaccessible LUN.
Deliver CAM_SEL_TIMEOUT to CAM upon SRB status errors as suggested by
Scott Long, other values seems improper.
This commit fixes the Hyper-V disk hotplug support.
Submitted by: Hongjiang Zhang <honzhan microsoft com>
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7521
Some devices report that they have an MRL when they actually
do not. Since they always report that the MRL is open, child
devices would be ignored. Try to detect these devices and
ignore their claim of HotPlug support. Specifically,
if there is an open MRL but the Data Link Layer is active,
the MRL is not real.
Revert r303645 to re-enable HotPlug support for slots with
power controllers, since it works correctly in my testing.
Start the DLL state-change timer if Presence /or/ MRL state changes,
along with other conditions. Previously, we started the timer iff
Presence changed. If there is an MRL, it must be closed for power
to be turned on, so Presence is unlikely to change on an MRL-close event.
Add a printf() of interesting registers on HotPlug interrupts and
commands (one from erj@). These were very useful for debugging.
Guard them with bootverbose, since they're spam in normal operation.
In collaboration with: jhb
Reviewed by: jhb
MFC after: 1 day
Relnotes: yes (re-enable HotPlug support for slots with power controllers)
Sponsored by: Dell Inc.
Differential Revision: https://reviews.freebsd.org/D7509
it (either async or sync drain).
At this moment the only user of drain is TCP, but TCP wouldn't reschedule a
callout after it has drained it, since it drains only when a tcpcb is closed.
This for now the problem isn't observed.
Submitted by: rrs
- Added a generic bhnd_nvram_parser API, with support for the TLV format
used on WGT634U devices, the standard BCM NVRAM format used on most
modern devices, and the "board text file" format used on some hardware
to supply external NVRAM data at runtime (e.g. via an EFI variable).
- Extended the bhnd_bus_if and bhnd_nvram_if interfaces to support both
string-based and primitive data type variable access, required for
common behavior across both SPROM and NVRAM data sources.
- Extended the existing SPROM implementation to support the new
string-based NVRAM APIs.
- Added an abstract bhnd_nvram driver, implementing the bhnd_nvram_if
atop the bhnd_nvram_parser API.
- Added a CFE-based bhnd_nvram driver to provide read-only access to
NVRAM data on MIPS SoCs, pending implementation of a flash-aware
bhnd_nvram driver.
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D7489
This replaces the bitfield representation of the bhndb register window
freelist with the bitstring API, eliminating a dependency on
(MIPS-unsupported) __builtin_ctz().
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D7495
with softupdates panics the kernel. The problem that has been pointed
out is that when there is a transient write error on certain metadata
blocks, specifically directory blocks (PAGEDEP), inode blocks
(INODEDEP), indirect pointer blocks (INDIRDEPS), and cylinder group
(BMSAFEMAP, but only when journaling is enabled), we get a panic
in one of the routines called by softdep_disk_io_initiation that
the I/O is "already started" when we retry the write.
These dependency types potentially need to do roll-backs when called
by softdep_disk_io_initiation before doing a write and then a
roll-forward when called by softdep_disk_write_complete after the
I/O completes. The panic happens when there is a transient error.
At the top of softdep_disk_write_complete we check to see if the
write had an error and if an error occurred we just return. This
return is correct most of the time because the main role of the routines
called by softdep_disk_write_complete is to process the now-completed
dependencies so that the next I/O steps can happen.
But for the four types listed above, they do not get to do their
rollback operations. This causes the panic when softdep_disk_io_initiation
gets called on the second attempt to do the write and the roll-back
routines find that the roll-backs have already been done. As an
aside I note that there is also the problem that the buffer will
have been unlocked and thus made visible to the filesystem and to
user applications with the roll-backs in place.
The way to resolve the problem is to add a flag to the routines called
by softdep_disk_write_complete for the four dependency types noted
that indicates whether the write was successful (WRITESUCCEEDED).
If the write does not succeed, they do just the roll-backs and then
return. If the write was successful they also do their usual
processing of the now-completed dependencies.
The fix was tested by selectively injecting write errors for buffers
holding dependencies of each of the four types noted above and then
verifying that the kernel no longer paniced and that following the
successful retry of the write that the filesystem could be unmounted
and successfully checked cleanly.
PR: 211013
Reviewed by: kib
allocation unwinding.
Dandling buffers are released on UFS_BALLOC() failure to ensure that
later attempt to allocate blocks in close range do not find the blocks
with invalid content, since possible partial block allocations are
unwound. As such, it is not enough to just release the buffers, the
pages must also invalidated and removed from the vnode vm_object
queue. Otherwise the pages might be found later and used to
reconstruct indirect buffers when doing allocations at offset close to
the failure point, and their stale content compromise the filesystem
integrity.
Note that just marking the buffer as B_INVAL is not enough, B_NOCACHE
is required. To be sure, clear the B_CACHE flag as well. This
complements the r174973, which started releasing buffers.
Reported and tested by: pho
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
that recorded allocated blocks numbers match the physical block
numbers of dandling buffers which are released.
When finally freeing the blocks during unwind, assert that dandling
buffers where not re-allocated. They shouldn't, because the vnode lock
is owned exclusive.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
queue.h header file and in the queue.3 manual page that they are O(n)
so should be used only in low-usage paths with short lists (otherwise
an STAILQ or TAILQ should be used).
Reviewed by: kib
have SU enabled, there is no point in calling softdep_request_cleanup().
The call cannot produce free blocks, but we unecessarily lock ufsmount
and do inode block write. Usual point of not doing optimizations for
the corner case of the full volume is not applicable there, the work
is easily avoidable, and the addition CPU and disk io load do not lead
to succeeding retry.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
overflow local arrays. This is not immediately obvious from the
static code inspection, due to retry logic.
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
alternate TCP stack in other then the closed state (pre-listen/connect).
The idea is that *if* that is supported by the alternate stack, it
is asked if its ok to switch. If it approves the "handoff" then we
allow the switch to happen. Also the fini() function now gets a flag
to tell if you are switching away *or* the tcb is destroyed. The
init() call into the alternate stack is moved to the end so the
tcb is more fully formed before the init transpires.
Sponsored by: Netflix Inc.
Differential Revision: D6790
Avoid unnecessary message type setting and centralize the send context
to transaction id cast.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7500
7085 add support for "if" and "else" statements in dtrace
illumos/illumos-gate@c3bd3abd88
Add syntactic sugar to dtrace: "if" and "else" statements. The sugar is
baked down to standard dtrace features by adding additional clauses with
the appropriate predicates.
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Matthew Ahrens <mahrens@delphix.com>
MFC after: 2 weeks
Relnotes: yes
7033 ustack helper should fault on bad return values
Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Approved by: Matthew Ahrens <mahrens@delphix.com>
Author: Alex Wilson <alex.wilson@joyent.com>
illumos/illumos-gate@a2f72b65eb
MFC after: 2 weeks
