Currently stats are collected in a MAXCPU-sized array which is not
aligned and suffers enormous false-sharing. Fix the problem by
utilizing per-cpu allocation.
The counter(9) API is not used here as it is too incomplete and does
not provide a win over per-cpu zone sized for malloc stats struct. In
particular stats are being reported for each cpu separately by just
copying what is supposed to be an array element for given cpu.
This eliminates significant false-sharing during malloc-heavy tests
e.g. on Skylake. See the review for details.
Reviewed by: markj
Approved by: re (kib)
Differential Revision: https://reviews.freebsd.org/D17289
The old code appears to assume that vmem_alloc() would import
size-aligned KVA chunks from the parent kernel_arena, but vmem doesn't
provide this guarantee.
Also remove the unused global RWX arena and add comments explaining why
we have per-domain arenas.
Reported by: alc
Reviewed by: alc, kib (previous version)
Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17249
UFS quotaoff iterates over all mp vnodes, and derefences and clears
the pointers to corresponding dquots. If SU work items transiently
reference some of dquots,quotaoff() would eventually fail, but all
processed vnodes are already stripped from dquots. The state is
problematic, since quotas are left enabled, but there is no dquots
where blocks and inodes can be accounted. The result is assertion
failures and NULL pointer dereferences.
Fix it by suspending writes around quotaoff() call. Since the
filesystem is synced, no dandling references to dquots from SU
workitems can left behind, which means that quotaoff succeeds.
The complication there is that quotaoff VFS op is performed with the
mount point busied, while to suspend, we need to start write on the
mp. If vn_start_write() is called on busied mp, system might deadlock
against parallel unmount request. Handle this by unbusy-ing mp before
starting write, which in turn requires changing the quotaoff()
interface to return with the mount point not busied, same as was done
for quotaon().
Reviewed by: mckusick
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
Approved by: re (gjb)
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D17208
Also remove some related and unused subroutines. They have long been
replaced by variants that handle multiple coalesced events with a single
call.
No functional change intended.
Reviewed by: cem, kib
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D17029
We will have last_block < blocks if the block count is divisible
by BLIST_BMAP_RADIX, but a terminator node is still needed if the
tree isn't balanced. In this case we were overruning the blist
array by 16 bytes during initialization.
While here, add a check for the invalid blocks == 0 case.
PR: 231116
Reviewed by: alc, kib (previous version), Doug Moore <dougm@rice.edu>
Approved by: re (gjb)
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17020
handling.
This is split into a separate commit from the main change to make it
easier to handle possible revert after upcoming KBI freeze.
Reviewed by: kevans
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (rgrimes)
Differential revision: https://reviews.freebsd.org/D16972
Print error message in verbose mode when CLOCK_SETTIME() clock_if.m
method failed. For EFIRT RTC clock, add error code for the failure of
CLOCK_GETTIME() report.
Reviewed by: kevans
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (rgrimes)
Differential revision: https://reviews.freebsd.org/D16972
given in random(4).
This includes updating of the relevant man pages, and no-longer-used
harvesting parameters.
Ensure that the pseudo-unit-test still does something useful, now also
with the "other" algorithm instead of Yarrow.
PR: 230870
Reviewed by: cem
Approved by: so(delphij,gtetlow)
Approved by: re(marius)
Differential Revision: https://reviews.freebsd.org/D16898
error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().
Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are
mapped in kmem with execute permissions. Use this flag to determine which
arena the kmem virtual addresses are returned to.
Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it
redundant.
Update the nearby comment for UMA_SLAB_KERNEL.
Reviewed by: kib, markj
Discussed with: jeff
Approved by: re (marius)
Differential Revision: https://reviews.freebsd.org/D16845
This flag is set once the device has been successfully attached. When
set, it inhibits devmatch from trying to match the device. This in
turn allows kldunload to work as expected. Prior to the change, the
driver would immediately reload because devmatch had no notion that
the driver had once been attached, and therefore shouldn't participate
in further matching.
Differential Revision: https://reviews.freebsd.org/D16735
This adds it to devctl, libdevctl, defines the two IOCTLs and
implements the kernel bits. causes any new drivers that are added via
kldload to be deferred until a 'thaw' comes in. These do not stack: it
is an error to freeze while frozen, or thaw while thawed.
Differential Revision: https://reviews.freebsd.org/D16735
No functional change.
When attempting to document the changed argument types in devstat.9, I
discovered the 20 year old manual page severely mismatched reality even
prior to my simple change. So I took a first cut pass cleaning that up to
match reality. I'm sure I've missed some things; the goal was just to leave
it better than when I started.
Sponsored by: Dell EMC Isilon
Add an option, KASSERT_PANIC_OPTIONAL, that allows runtime KASSERT()
behavior changes. When this option is not enabled, code that allows
KASSERTs to become optional is not enabled, and all violated assertions
cause termination.
The runtime KASSERT behavior was added in r243980.
One important distinction here is that panic has __dead2
("attribute((noreturn))"), while kassert_panic does not. Static analyzers
like Coverity understand __dead2. Without it, KASSERTs go misunderstood,
resulting in many false positives that result from violation of program
invariants.
Reviewed by: jhb, jtl, np, vangyzen
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16835
The boot-time ifunc resolver assumes that it only needs to apply
IRELATIVE relocations to PLT entries. With an upcoming optimization,
this assumption no longer holds, so add the support required to handle
PC-relative relocations targeting GNU_IFUNC symbols.
- Provide a custom symbol lookup routine that can be used in early boot.
The default lookup routine uses kobj, which is not functional at that
point.
- Apply all existing relocations during boot rather than filtering
IRELATIVE relocations.
- Ensure that we continue to apply ifunc relocations in a second pass
when loading a kernel module.
Reviewed by: kib
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16749
the domain of a socket.
This is helpful when testing and Solaris and Linux have the same
socket option using the same name.
Reviewed by: bcr@, rrs@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16791
The fallback logic was broken if hints were found in multiple environments.
If we found a hint in either the loader environment or the static
environment, fallback would be incremented excessively when we returned to
the environment-selection bits. These checks should have also been guarded
by the fbacklvl checks. As a result, fbacklvl could quickly get to a point
where we skip either the static environment and/or the static hints
depending on which environments contained valid hints.
The impact of this bug is minimal, mostly affecting mips boards that use
static hints and may have hints in either the loader environment or the
static environment.
There may be better ways to express the searchable environments and
describing their characteristics (immutable, already searched, etc.) but
this may be revisited after 12 branches.
Reported by: Dan Nelson <dnelson_1901@yahoo.com>
Triaged by: Dan Nelson <dnelson_1901@yahoo.com>
MFC after: 3 days
Some internal KASSERTs access the v_iflag field without the vnode
interlock held after such a refcount update. The fences are needed for
the assertions to be correct in the face of store reordering.
Reported and tested by: jhibbits
Reviewed by: kib, mjg
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16756
Capsicum in past allowed to change the process title.
This was broken with r335939.
PR: 230584
Submitted by: Yuichiro NAITO <naito.yuichiro@gmail.com>
Reported by: ian@niw.com.au
MFC after: 1 week
This change allows one to set kern.boot_tag="" and not get a blank line
preceding other boot messages. While this isn't super critical- blank lines
are easy to filter out both mentally and in processing dmesg later- it
allows for a mode of operation that matches previous behavior.
I intend to MFC this whole series to stable/11 by the end of the month with
boot_tag empty by default to make this effectively a nop in the stable
branch.
jails since FreeBSD 7.
Along with the system call, put the various security.jail.allow_foo and
security.jail.foo_allowed sysctls partly under COMPAT_FREEBSD11 (or
BURN_BRIDGES). These sysctls had two disparate uses: on the system side,
they were global permissions for jails created via jail(2) which lacked
fine-grained permission controls; inside a jail, they're read-only
descriptions of what the current jail is allowed to do. The first use
is obsolete along with jail(2), but keep them for the second-read-only use.
Differential Revision: D14791
msgbufinit may be called multiple times as we initialize the msgbuf into a
progressively larger buffer. This doesn't happen as of now on head, but it
may happen in the future and we generally support this. As such, only print
the boot tag if we've just initialized the buffer for the first time.
The boot tag also now has a newline appended to it for better visibility,
and has been switched to a normal printf, by requesto f bde, after we've
denoted that the msgbuf is mapped.
BOOT_TAG lived shortly in sys/msgbuf.h, but this wasn't necessarily great
for changing it or removing it. Move it into subr_prf.c and add options for
it to opt_printf.h.
One can specify both the BOOT_TAG and BOOT_TAG_SZ (really, size of the
buffer that holds the BOOT_TAG). We expose it as kern.boot_tag and also add
a loader tunable by the same name that we'll fetch upon initialization of
the msgbuf.
This allows for flexibility and also ensures that there's a consistent way
to figure out the boot tag of the running kernel, rather than relying on
headers to be in-sync.
Prodded super-super-lightly by: imp
On PowerPC (and possibly other architectures), that doesn't use
EARLY_AP_STARTUP, the config task queue may be used initialized.
This was observed while trying to mount the root fs from NFS, as
reported here: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230168.
This patch has 2 main changes:
1- Perform a basic initialization of qgroup_config, similar to
what is done in taskqgroup_adjust, but simpler.
This makes qgroup_config ready to be used during NFS root mount.
2- When EARLY_AP_STARTUP is not used, call inm_init() and
in6m_init() right before SI_SUB_ROOT_CONF, because bootp needs
to send multicast packages to request an IP.
PR: Bug 230168
Reported by: sbruno
Reviewed by: jhibbits, mmacy, sbruno
Approved by: jhibbits
Differential Revision: D16633
From the "newly licensed to drive" PR department, add a BOOT_TAG marker (by
default, --<<BOOT>>--, to the beginning of each boot's dmesg. This makes it
easier to do textproc magic to locate the start of each boot and, of
particular interest to some, the dmesg of the current boot.
The PR has a dmesg(8) component as well that I've opted not to include for
the moment- it was the more contentious part of this PR.
bde@ also made the statement that this boot tag should be written with an
ordinary printf, which I've- for the moment- declined to change about this
patch to keep it more transparent to observer of the boot process.
PR: 43434
Submitted by: dak <aurelien.nephtali@wanadoo.fr> (basically rewritten)
MFC after: maybe never
If a recvmsg(2) or recvmmsg(2) caller doesn't provide sufficient space
for all control messages, the kernel sets MSG_CTRUNC in the message
flags to indicate truncation of the control messages. In the case
of SCM_RIGHTS messages, however, we were failing to dispose of the
rights that had already been externalized into the recipient's file
descriptor table. Add a new function and mbuf type to handle this
cleanup task, and use it any time we fail to copy control messages
out to the recipient. To simplify cleanup, control message truncation
is now only performed at control message boundaries.
The change also fixes a few related bugs:
- Rights could be leaked to the recipient process if an error occurred
while copying out a message's contents.
- We failed to set MSG_CTRUNC if the truncation occurred on a control
message boundary, e.g., if the caller received two control messages
and provided only the exact amount of buffer space needed for the
first.
PR: 131876
Reviewed by: ed (previous version)
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16561
Swapped-out process that is WKILLED must be swapped in as soon as
possible. The reason is that such process can be killed by OOM and
its pages can be only freed if the process exits. To exit, the kernel
stack of the process must be mapped.
When allocating pages for the stack of the WKILLED process on swap in,
use VM_ALLOC_SYSTEM requests to increase the chance of the allocation
to succeed.
Add counter of the swapped out processes to avoid unneeded iteration
over the allprocs list when there is no work to do, reducing the
allproc_lock ownership.
Reviewed by: alc, markj (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D16489
sosend_generic() performs an initial comparison of the amount of data
(including control messages) to be transmitted with the send buffer
size. When transmitting on a unix socket, we then compare the amount
of data being sent with the amount of space in the receive buffer size;
if insufficient space is available, sbappendcontrol() returns an error
and the data is lost. This is easily triggered by sending control
messages together with an amount of data roughly equal to the send
buffer size, since the control message size may change in uipc_send()
as file descriptors are internalized.
Fix the problem by removing the space check in sbappendcontrol(),
whose only consumer is the unix sockets code. The stream sockets code
uses the SB_STOP mechanism to ensure that senders will block if the
receive buffer fills up.
PR: 181741
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16515
The code that iterates a list of interrupt handlers for a (shared)
interrupt, whether in the ISR context or in the context of an interrupt
thread, does so in a lock-free fashion. Thus, the routines that modify
the list need to take special steps to ensure that the iterating code
has a consistent view of the list. Previously, those routines tried to
play nice only with the code running in the ithread context. The
iteration in the ISR context was left to a chance.
After commit r336635 atomic operations and memory fences are used to
ensure that ie_handlers list is always safe to navigate with respect to
inserting and removal of list elements.
There is still a question of when it is safe to actually free a removed
element.
The idea of this change is somewhat similar to the idea of the epoch
based reclamation. There are some simplifications comparing to the
general epoch based reclamation. All writers are serialized using a
mutex, so we do not need to worry about concurrent modifications. Also,
all read accesses from the open context are serialized too.
So, we can get away just two epochs / phases. When a thread removes an
element it switches the global phase from the current phase to the other
and then drains the previous phase. Only after the draining the removed
element gets actually freed. The code that iterates the list in the ISR
context takes a snapshot of the global phase and then increments the use
count of that phase before iterating the list. The use count (in the
same phase) is decremented after the iteration. This should ensure that
there should be no iteration over the removed element when its gets
freed.
This commit also simplifies the coordination with the interrupt thread
context. Now we always schedule the interrupt thread when removing one
of handlers for its interrupt. This makes the code both simpler and
safer as the interrupt thread masks the interrupt thus ensuring that
there is no interaction with the ISR context.
P.S. This change matters only for shared interrupts and I realize that
those are becoming a thing of the past (and quickly). I also understand
that the problem that I am trying to solve is extremely rare.
PR: 229106
Reviewed by: cem
Discussed with: Samy Al Bahra
MFC after: 5 weeks
Differential Revision: https://reviews.freebsd.org/D15905
Enable the LOCAL_PEERCRED socket option for unix domain stream sockets
created with socketpair(2). Previously, it only worked with unix domain
stream sockets created with socket(2)/listen(2)/connect(2)/accept(2).
PR: 176419
Reported by: Nicholas Wilson <nicholas@nicholaswilson.me.uk>
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D16350
The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have grown at least 28 syscalls that use timespecs in some
way, leading many programs both inside and outside of the base system to
redefine those macros. It's better just to make the definitions public.
Our kernel currently defines two-argument versions of timespecadd and
timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define
three-argument versions. Solaris also defines a three-argument version, but
only in its kernel. This revision changes our definition to match the
common three-argument version.
Bump _FreeBSD_version due to the breaking KPI change.
Discussed with: cem, jilles, ian, bde
Differential Revision: https://reviews.freebsd.org/D14725
It allows locking or unlocking physical pages in memory within a jail
This allows running elasticsearch with "bootstrap.memory_lock" inside a jail
Reviewed by: jamie@
Differential Revision: https://reviews.freebsd.org/D16342
initial call to sched_balance() during startup is meant to initialize
balance_ticks, but does not actually do that since smp_started is
still zero at that time. Since balance_ticks does not get set,
there are no further calls to sched_balance(). Fix this by setting
balance_ticks in sched_initticks() since we know the value of
balance_interval at that time, and eliminate the useless startup
call to sched_balance(). We don't need to randomize the intial
value of balance_ticks.
Since there is now only one call to sched_balance(), we can hoist
the tests at the top of this function out to the caller and avoid
the overhead of the function call when running a SMP kernel on UP
hardware.
PR: 223914
Reviewed by: kib
MFC after: 2 weeks
If a timer is updated (re-added) with a different time period
(specified in the .data field of the kevent), the new time period has
no effect; the timer will not expire until the original time has
elapsed. This violates the documented behavior as the kqueue(2) man
page says (in part) "Re-adding an existing event will modify the
parameters of the original event, and not result in a duplicate
entry."
This modification, adapted from a patch submitted by cem@ to PR214987,
fixes the kqueue system to allow updating a timer entry. The
kevent timer behavior is changed to:
* When a timer is re-added, update the timer parameters to and
re-start the timer using the new parameters.
* Allow updating both active and already expired timers.
* When the timer has already expired, dequeue any undelivered events
and clear the count of expirations.
All of these changes address the original PR and also bring the
FreeBSD and macOS kevent timer behaviors into agreement.
A few other changes were made along the way:
* Update the kqueue(2) man page to reflect the new timer behavior.
* Fix man page style issues in kqueue(2) diagnosed by igor.
* Update the timer libkqueue system test to test for the updated
timer behavior.
* Fix the (test) libkqueue common.h file so that it includes
config.h which defines various HAVE_* feature defines, before the
#if tests for such variables in common.h. This enables the use of
the actual err(3) family of functions.
* Fix the usages of the err(3) functions in the tests for incorrect
type of variables. Those were formerly undiagnosed due to the
disablement of the err(3) functions (see previous bullet point).
PR: 214987
Reported by: Brian Wellington <bwelling@xbill.org>
Reviewed by: kib
MFC after: 1 week
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D15778
The primary reason for this commit is to separate mechanical and nearly
mechanical code changes from an upcoming fix for unsafe teardown of
shared interrupt handlers that have only filters (see D15905).
The technical rationale is that SLIST is sufficient. The only operation
that gets worse performance -- O(n) instead of O(1) is a removal of a
handler, but it is not a critical operation and the list is expected to
be rather short.
Additionally, it is easier to reason about SLIST when considering the
concurrent lock-free access to the list from the interrupt context and
the interrupt thread.
CK_SLIST is used because the upcoming change depends on the memory order
provided by CK_SLIST insert and the fact that CL_SLIST remove does not
trash the linkage in a removed element.
While here, I also fixed a couple of whitespace issues, made code under
ifdef notyet compilable, added a lock assertion to ithread_update() and
made intr_event_execute_handlers() static as it had no external callers.
Reviewed by: cem (earlier version)
MFC after: 4 weeks
Differential Revision: https://reviews.freebsd.org/D16016
Some driver (like efifb) needs to map more than the current L2_SIZE
Raise the size so we can map the framebuffer setup by the bootloader.
Reviewed by: cognet
On i386 and amd64, add a vm_phys segment for physical memory used to
store the kernel binary and other preloaded data. This makes it
possible to free such memory back to the system once it is no longer
needed, e.g., when a preloaded kernel module is unloaded. Previously,
it would have remained unused.
Reviewed by: kib, royger
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16330
The basename will never match against the preload metadata, so these
calls previously had no effect.
Reviewed by: kib, royger
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16330
to it being a common name elsewhere. Rename the old kzip one
to subr_inflate.c.
This actually fixes the build issues on sparc64 that my inclusion of
.PATH ${SYSDIR}/kern created in r336244, so also revert the broken
workaround I committed in r336249.
This slipped passed me because apparently, I never did a clean build.
boot_parse_arg to parse a single arg
boot_parse_cmdline to parse a command line string
boot_parse_args to parse all the args in a vector
boot_howto_to_env Convert howto bits to env vars
boot_env_to_howto Return howto mask mased on what's set in the environment.
All these routines return an int that's the bitmask of the args
translated to RB_* flags. As a special case, the 'S' flag sets the
comconsole_speed env var. Any arg that looks like a=b will set the env
key 'a' to value 'b'. If =b is omitted, 'a' is set to '1'. This
should help us reduce the number of redundant copies of these routines
in the tree. It should also give a more uniform experience between
platforms.
Also, invent a new flag RB_PROBE that's set when 'P' is parsed. On
x86 + BIOS, this means 'probe for the keyboard, and if it's not there
set both RB_MULTIPLE and RB_SERIAL (which means show the output on
both video and serial consoles, but make serial primary). Others it
may be some similar concept of probing, but it's loader dependent
what, exactly, it means.
These routines are suitable for /boot/loader and/or the kernel,
though they may not be suitable for the tightly hand-rolled-for-space
environments like boot2.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D16205
In practice, this moves the padding from below the canary to above
execpathp has no impact on stack consumption.
Submitted by: Wuyang-Chung (via github pull request #159)
MFC after: 1 week
This variable has been given the name "loader_env.disabled" as it's the
primary way most people will have an MD environment. This restores the
previously-default behavior of ignoring the loader(8) environment, which may
be useful for vendor distributions or other scenarios where inheriting the
loader environment may be considered a security issue or potentially
breaking of a more locked-down environment.
As the change to config(5) indicates, disabling the loader environment
should not be a choice made lightly since it may provide ACPI hints and
other useful things that the system can rely on to boot.
An UPDATING entry has been added to mention an upgrade path for those that
may have relied on the previous behavior.
Discussed with: bde
Relnotes: yes (maybe)
When the "pc" audit class is enabled and auditd is running, witness will
panic during thread exit because au_event_class tries to lock an rwlock
while holding a spinlock acquired upstack by thread_exit.
To fix this, move AUDIT_SYSCALL_EXIT futher upstack, before the spinlock is
acquired. Of thread_exit's 16 callers, it's only necessary to call
AUDIT_SYSCALL_EXIT from two, exit1 (for exiting processes) and kern_thr_exit
(for exiting threads). The other callers are all kernel threads, which
needen't call AUDIT_SYSCALL_EXIT because since they can't make syscalls
there will be nothing to audit. And exit1 already does call
AUDIT_SYSCALL_EXIT, making the second call in thread_exit redundant for that
case.
PR: 228444
Reported by: aniketp
Reviewed by: aniketp, kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D16210
No valid FreeBSD binary very called them (they would call lchown and
msync directly) and we haven't supported NetBSD binaries in ages.
This is a respin of r335983 with a workaround for the ancient BFD linker
in the libc stubs.
Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D16193
This is possible because, well, they're static. Both the dynamic environment
and the MD-environment (generally loader(8) environment) can potentially
have room for new variables to be set, and thus do not receive this
treatment.
r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the
backend allocator for PCPU UMA zones. Unlike page_alloc(), it does
not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that.
r336020 also changed counter(9) to initialize each counter using a
CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU,
smp_rendezvous() will only execute the callback on the current CPU
(i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed
by virtue of the fact that UMA gratuitously zeroes slabs when importing
them into a zone.
Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't
zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no
effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by
iterating over the full range of CPU IDs when zeroing counters,
ignoring whether the corresponding bits in all_cpus are set.
Reported and tested by: pho (previous version)
Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D16190
The dynamic environment was being initialized at SI_SUB_KMEM, SI_ORDER_ANY.
I added the hint-merging at SI_SUB_KMEM, SI_ORDER_ANY as well in r335998 -
this can only work by coincidence.
Re-do both to operate at SI_SUB_KMEM + 1, SI_ORDER_FIRST and SI_ORDER_SECOND
respectively to be safe. It's sufficiently obfuscated away as to when in
SU_SUB_KMEM malloc will be available, and the dynamic environment cannot be
relied upon there anyways since it's initialized at SI_ORDER_ANY.
Reported by: bde
Discussed with: bde
X-MFC-With: r335998
- Change pcpu zone consumers to use a stride size of PAGE_SIZE.
(defined as UMA_PCPU_ALLOC_SIZE to make future identification easier)
- Allocate page from the correct domain for a given cpu.
- Don't initialize pc_domain to non-zero value if NUMA is not defined
There are some misconceptions surrounding this field. It is the
_VM_ NUMA domain and should only ever correspond to valid domain
values as understood by the VM.
The former slab size of sizeof(struct pcpu) was somewhat arbitrary.
The new value is PAGE_SIZE because that's the smallest granularity
which the VM can allocate a slab for a given domain. If you have
fewer than PAGE_SIZE/8 counters on your system there will be some
memory wasted, but this is obviously something where you want the
cache line to be coming from the correct domain.
Reviewed by: jeff
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15933
On arm64 (and possible other architectures) we are unable to use static
DPCPU data in kernel modules. This is because the compiler will generate
PC-relative accesses, however the runtime-linker expects to be able to
relocate these.
In preparation to fix this create two macros depending on if the data is
global or static.
Reviewed by: bz, emaste, markj
Sponsored by: ABT Systems Ltd
Differential Revision: https://reviews.freebsd.org/D16140
further changes adding another level of indentation.
Some of the logic got simplified with the break out functions.
There should be no functional changes.
Reviewed by: kib
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D15914
At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel config(5) and the
static versions are mutually exclusive with loader(8)-provided environment.
hintmode *can* be reconfigured later to pull from the dynamic environment,
thus taking advantage of the loader(8) or post-kmem environment setting.
This changeset fixes both problems at once to move us from a semi-confusing
state to a consistent state: if an environment file, hints file, or
loader(8) environment are provided, we use them in a well-known order of
precedence:
- loader(8) environment
- static environment
- static hints file
Once the dynamic environment is setup this becomes a moot point. The
loader(8) and static environments are merged (respecting the above order of
precedence), and the static hints are merged in on an as-needed basis after
the dynamic environment has been setup.
Hints lookup are changed to respect all of the above. Before the dynamic
environment is setup, lookups use the above-mentioned order and fallback to
the next environment if a matching hint is not found. Once the dynamic
environment is setup, that is used on its own since it captures all of the
above information plus any dynamic kenv settings that came up later in boot.
The following tangentially related changes were made to res_find:
- A hintp cookie is now passed in so that related searches continue using
the chain of environments (or dynamic environment) without relying on
global state
- All three environments will be searched if they actually have valid hints
to use, rather than just choosing the first environment that actually had
a hint and rolling with that only
The hintmode sysctl has been ripped out. static_{env,hints}.disabled are
still honored and will disable their respective environments from being used
for hint lookups and from being merged into the dynamic environment, as
expected.
MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15953
At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel config(5) and the
static versions are mutually exclusive with loader(8)-provided environment.
hintmode *can* be reconfigured later to pull from the dynamic environment,
thus taking advantage of the loader(8) or post-kmem environment setting.
This changeset fixes both problems at once to move us from a semi-confusing
state to a consistent state: if an environment file, hints file, or
loader(8) environment are provided, we use them in a well-known order of
precedence:
- loader(8) environment
- static environment
- static hints file
Once the dynamic environment is setup this becomes a moot point. The
loader(8) and static environments are merged (respecting the above order of
precedence), and the static hints are merged in on an as-needed basis after
the dynamic environment has been setup.
Hints lookup are changed to respect all of the above. Before the dynamic
environment is setup, lookups use the above-mentioned order and fallback to
the next environment if a matching hint is not found. Once the dynamic
environment is setup, that is used on its own since it captures all of the
above information plus any dynamic kenv settings that came up later in boot.
The following tangentially related changes were made to res_find:
- A hintp cookie is now passed in so that related searches continue using
the chain of environments (or dynamic environment) without relying on
global state
- All three environments will be searched if they actually have valid hints
to use, rather than just choosing the first environment that actually had
a hint and rolling with that only
The hintmode sysctl has been ripped out. static_{env,hints}.disabled are
still honored and will disable their respective environments from being used
for hint lookups and from being merged into the dynamic environment, as
expected.
MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15953
proc0 and init are setup as a circular dependency.
create_init() calls fork1() which calls do_fork(). There the
newproc (initproc) is setup with a reaper of proc0 who's reaper
points to itself. The newproc (initproc) is then put on its
reaper's (proc0) p_reaplist (initproc is a descendants of proc0
for proc0 to reap). Upon return to create_init(), proc0 is
added to initproc's p_reaplist (which would mean proc0 is a
descendant of init, for init to reap). This creates a
circular dependency which eventually leads to LIST corruptions
when trying to kill init and a proc0.
For the base system we never really hit this case during reboot.
The problem only became visible after adding more virtual process
spaces which could go away cleanly (work existing in an experimental
branch).
Reviewed by: kib
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D15924
No valid FreeBSD binary ever called them (they would call lchown and
msync directly) and we haven't supported NetBSD binaries in ages.
Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15814
Replace size_t members with ksize_t (uint64_t) and pointer members
(never used as pointers in userspace, but instead as unique
idenitifiers) with kvaddr_t (uint64_t). This makes the structs
identical between 32-bit and 64-bit ABIs.
On 64-bit bit systems, the ABI is maintained. On 32-bit systems,
this is an ABI breaking change. The ABI of most of these structs
was previously broken in r315662. This also imposes a small API
change on userspace consumers who must handle kernel pointers
becoming virtual addresses.
PR: 228301 (exp-run by antoine)
Reviewed by: jtl, kib, rwatson (various versions)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15386
the process arguments. New arguments length zero causes the drop of
the pargs instead of allocation of useless zero-length buffer.
Submitted by: Thomas Munro
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16111
It's likely that the header was needed in the past for swi(9).
But now that code does not use swi(9) or any other interfaces defined
in sys/interrupt.h.
MFC after: 1 week
- Add tracker argument to preemptible epochs
- Inline epoch read path in kernel and tied modules
- Change in_epoch to take an epoch as argument
- Simplify tfb_tcp_do_segment to not take a ti_locked argument,
there's no longer any benefit to dropping the pcbinfo lock
and trying to do so just adds an error prone branchfest to
these functions
- Remove cases of same function recursion on the epoch as
recursing is no longer free.
- Remove the the TAILQ_ENTRY and epoch_section from struct
thread as the tracker field is now stack or heap allocated
as appropriate.
Tested by: pho and Limelight Networks
Reviewed by: kbowling at llnw dot com
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16066
Avoid pulling in all of the <sys/proc.h> dependencies by
automatically generating a stripped down thread_lite exporting
only the fields of interest. The field declarations are type checked
against the original and the offsets of the generated result is
automatically checked.
kib has expressed disagreement and would have preferred to simply
use genassym style offsets (which loses type check enforcement).
jhb has expressed dislike of it due to header pollution and a
duplicate structure. He would have preferred to just have defined
thread in _thread.h. Nonetheless, he admits that this is the only
viable solution at the moment.
The impetus for this came from mjg's D15331:
"Inline critical_enter/exit for amd64"
Reviewed by: jeff
Differential Revision: https://reviews.freebsd.org/D16078
The '%I' format in the kern.corefile sysctl limits the number of
core files that a process can generate to the number stored in the
debug.ncores sysctl. The '%I' format is replaced by the single digit
index. Previously, if all indexes were taken the kernel would overwrite
only a core file with the highest index in a filename.
Currently the system will create a new core file if there is a free
index or if all slots are taken it will overwrite the oldest one.
Reviewed by: kib(code), bcr (updating)
Differential Revision: https://reviews.freebsd.org/D15991
Differential Revision: https://reviews.freebsd.org/D16084
We have a problem with vn_fullpath_global when the file exists. Work
around it by printing the full path if the core file name starts with /,
or current working directory followed by the filename if not.
Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D16026
sbuf to make it safe. Callers are expected to add the " " around it,
if needed.
Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D16026
If EARLY_AP_STARTUP is not defined it is possible for an epoch to be
allocated prior to it being possible to call epoch_call without
issue.
Based on patch by andrew@
PR: 229014
Reported by: andrew
used portion of the current thread's time slice if the current thread
belongs to the process being queried (i.e., if clock_gettime is invoked
with a clock ID of CLOCK_PROCESS_CPUTIME_ID or the value provided by
passing getpid(2) to clock_getcpuclockid(3)).
The CLOCK_VIRTUAL and CLOCK_PROF timers already make this adjustment via
long-standing code in calcru(), but since those timers are not specified
by POSIX it seems useful to add it here so that the higher accuracy is
available to code which aims to be portable.
PR: 228669
Reported by: Graham Percival
Reviewed by: kib
MFC after: 1 week
The refactoring in r335479 overlooked the fact that the dynamic kenv can
also be switched to if hintmode == 0. This is problematic because the
checkmethod bits are only ever ran once, but it worked previously because
the use_kenv was a global state and the first lookup would enable it if
occurring after the dynamic environment has been setup.
Extending our local definition of use_kenv to include all non-STATIC
hintmodes as long as the dynamic_kenv is setup fixes this. We still have
potential issues if the dynamic kenv comes up while we're doing an anchored
search through the environment, but this is not much of a concern right now
because:
1.) The dynamic environment comes up super early in boot, just after kmem
2.) This is going to get rewritten to provide a safer mechanism for the
anchored searches, ensuring that we continue using the same environment
chain (dynamic env or static fallback) for all anchored search invocations
Reported by: mmamcy
X-MFC-With: r335479
An RFSTOPPED thread can't clean TDB_STOPATFORK, which is done in the
fork_return() in its context, so parent is stuck forever. Triggered
when trying to ptrace linux process. Instead of waiting for the new
thread to clear TDB_STOPATFORK, tag it as traced and reparent to the
debugger in do_fork(), and let it only notify the debugger when run.
Submitted by: Yanko Yankulov <yanko.yankulov@gmail.com>
Reviewed by: jhb
MFC after: 1 week
X-MFC-Note: keep p_dbgwait placeholder intact
Differential revision: https://reviews.freebsd.org/D15857
Summary: POWER8 and POWER9 use a single CPU register, per core, to change clock
speed. Everything else is handled by the on-chip controller. This change
necessitates a change to the cpufreq global kernel driver to bump supported
levels, as the device tree for these systems can have theoretically 256
different options. On my POWER9 Talos, the list consists of 100 items. At
16.67MHz intervals, that allows for a change of roughly 1.67GHz between lowest
and highest.
This has only been tested on the POWER9. However, since they're similar, this
should work on POWER8 as well.
Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D15932
Some complexity exists in these bits that isn't needed. The sysctl handler,
upon change to '2', runs through the current set of hints and sets them in
the kenv.
However, this isn't at all necessary if we're pulling hints from the kenv,
static or dynamic, as the former will get added to the latter in
init_dynamic_kenv (see: kern_environment.c). We can reduce this
configuration to just adding static_hints to the kenv if we were previously
using them.
The changes in res_find are minimal and based on the observation that once
use_kenv gets set to '1' it will never be reset to '0', and it gets set to
'1' as soon as we hit fallback mode. Later work will refactor res_find a
little bit and eliminate this now-local, because it's become clear that
there's some funkiness revolving around use_kenv=1 and it being used to
imply that we're certainly looking at the dynamic_kenv.
Reviewed by: ray
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D15940
VERBOSE_SYSINIT is currently an all-or-nothing option. debug.verbose_sysinit
adds an option to have the code compiled in but quiet by default so that
getting this information from a device in the field doesn't necessarily
require distributing a recompiled kernel.
Its default is VERBOSE_SYSINIT's value as defined in the kernconf. As such,
the default behavior for simply omitting or including this option is
unchanged.
MFC after: 1 week
This is needed for efifb.
arm and ricv pmap (the two arch with arm64 that uses subr_devmap) have very
different implementation so for now only add this for arm64.
Tested with efifb on Pine64 with a few other patches.
Reviewed by: cognet
Differential Revision: https://reviews.freebsd.org/D15294
to FOREACH_PROC_IN_SYSTEM() to have a single pattern to look for.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D15916
Implement a ddb function walking the namecache to do this.
Reviewed by: jhb, mjg
Inspired by: gdb macro from jhb (old version)
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D14898
- Convert inpcbinfo info & hash locks to epoch for read and mutex for write
- Garbage collect code that handled INP_INFO_TRY_RLOCK failures as
INP_INFO_RLOCK which can no longer fail
When running 64 netperfs sending minimal sized packets on a 2x8x2 reduces
unhalted core cycles samples in rwlock rlock/runlock in udp_send from 51% to
3%.
Overall packet throughput rate limited by CPU affinity and NIC driver design
choices.
On the receiver unhalted core cycles samples in in_pcblookup_hash went from
13% to to 1.6%
Tested by LLNW and pho@
Reviewed by: jtl
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15686
Using of rwlock with multiqueue NICs for IP forwarding on high pps
produces high lock contention and inefficient. Rmlock fits better for
such workloads.
Reviewed by: melifaro, olivier
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D15789
counter_rate will be greater than ticks, resulting in counter_ratecheck()
failure. To fix this take an absolute value of the difference between
ticks and cr_ticks.
Reported by: jtl
Sponsored by: Netflix
- Filter out PRS_NEW procs as rufetch() tries taking the thread lock
which may not yet be initialized.
- Hold PROC_LOCK to ensure stability of iterating the threads.
- p_rux fields are protected by the process statlock as well.
MFC after: 2 weeks
Reviewed by: kib
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D15809
The break() system call was renamed (several times) starting in v3
AT&T UNIX when C was invented and break was a language keyword. The
last vestage of a need for it to be called something else (eg obreak)
was removed in r225617 which consistantly prefixed all syscall
implementations.
Reviewed by: emaste, kib (older version)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15638
Most kernel memory that is allocated after boot does not need to be
executable. There are a few exceptions. For example, kernel modules
do need executable memory, but they don't use UMA or malloc(9). The
BPF JIT compiler also needs executable memory and did use malloc(9)
until r317072.
(Note that a side effect of r316767 was that the "small allocation"
path in UMA on amd64 already returned non-executable memory. This
meant that some calls to malloc(9) or the UMA zone(9) allocator could
return executable memory, while others could return non-executable
memory. This change makes the behavior consistent.)
This change makes malloc(9) return non-executable memory unless the new
M_EXEC flag is specified. After this change, the UMA zone(9) allocator
will always return non-executable memory, and a KASSERT will catch
attempts to use the M_EXEC flag to allocate executable memory using
uma_zalloc() or its variants.
Allocations that do need executable memory have various choices. They
may use the M_EXEC flag to malloc(9), or they may use a different VM
interfact to obtain executable pages.
Now that malloc(9) again allows executable allocations, this change also
reverts most of r317072.
PR: 228927
Reviewed by: alc, kib, markj, jhb (previous version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D15691
Allow one to implement a 'car limit' for
bioq_disksort. debug.bioq_batchsize sets the size of car limit. Every
time we queue that many requests, we start over so that we limit the
latency for requests when the software queue depths are large. A value
of '0', the default, means to revert to the old behavior.
Sponsored by: Netflix
the old encodings for the lower 16 and 32 bits and only using the
higher 32 bits for unusually large major and minor numbers. This
change breaks compatibility with the previous encoding (which was only
used in -current).
Fix truncation to (essentially) 16-bit dev_t in newnfs v3.
Any encoding of device numbers gives an ABI, so it can't be changed
without translations for compatibility. Extra bits give the much
larger complication that the translations need to compress into fewer
bits. Fortunately, more than 32 bits are rarely needed, so
compression is rarely needed except for 16-bit linux dev_t where it
was always needed but never done.
The previous encoding moved the major number into the top 32 bits.
Almost no translation code handled this, so the major number was blindly
truncated away in most 32-bit encodings. E.g., for ffs, mknod(8) with
major = 1 and minor = 2 gave dev_t = 0x10000002; ffs cannot represent
this and blindly truncated it to 2. But if this mknod was run on any
released version of FreeBSD, it gives dev_t = 0x102. ffs can represent
this, but in the previous encoding it was not decoded, giving major = 0,
minor = 0x102.
The presence of bugs was most obvious for exporting dev_t's from an
old system to -current, since bugs in newnfs augment them. I fixed
oldnfs to support 32-bit dev_t in 1996 (r16634), but this regressed
to 16-bit dev_t in newnfs, first to the old 16-bit encoding and then
further in -current. E.g., old ad0 with major = 234, minor = 0x10002
had the correct (major, minor) number on the wire, but newnfs truncated
this to (234, 2) and then the previous encoding shifted the major
number into oblivion as seen by ffs or old applications.
I first tried to fix this by translating on every ABI/API boundary, but
there are too many boundaries and too many sloppy translations by blind
truncation. So use the old encoding for the low 32 bits so that sloppy
translations work no worse than before provided the high 32 bits are
not set. Add some error checking for when bits are lost. Keep not
doing any error checking for translations for almost everything in
compat/linux.
compat/freebsd32/freebsd32_misc.c:
Optionally check for losing bits after possibly-truncating assignments as
before.
compat/linux/linux_stats.c:
Depend on the representation being compatible with Linux's (or just with
itself for local use) and spell some of the translations as assignments in
a macro that hides the details.
fs/nfsclient/nfs_clcomsubs.c:
Essentially the same fix as in 1996, except there is now no possible
truncation in makedev() itself. Also fix nearby style bugs.
kern/vfs_syscalls.c:
As for freebsd32. Also update the sysctl description to include file
numbers, and change it to describe device ids as device numbers.
sys/types.h:
Use inline functions (wrapped by macros) since the expressions are now
a bit too complicated for plain macros. Describe the encoding and
some of the reasons for it. 16-bit compatibility didn't leave many
reasonable choices for the 32-bit encoding, and 32-bit compatibility
doesn't leave many reasonable choices for the 64-bit encoding. My
choice is to put the 8 new minor bits in the low 8 bits of the top 32
bits. This minimizes discontiguities.
Reviewed by: kib (except for rewrite of the comment in linux_stats.c)
of 64-bit dev_t's (but not ones involving dev_t's).
st_size was supposed to be clamped in cvtstat() and linux's copy_stat(),
but the clamping code wasn't aware that st_size is signed, and also had
an obfuscated off-by-1 value for the unsigned limit, so its effect was
to produce a bizarre negative size instead of clamping.
Change freebsd32's copy_ostat() to be no worse than cvtstat(). It was
missing clamping and bzero()ing of padding.
Reviewed by: kib (except a final fix of the clamp to the signed maximum)
- non NULL controlp is not an error, returning EINVAL
would cause X forwarding to fail
- MSG_PEEK and MSG_WAITALL are fairly exceptional, but we still
want to handle them - punt to soreceive_generic
callbacks to perform additional cleanup actions at the time a socket is
closed.
Michio Honda presented a use for this at BSDCan 2018.
(See https://www.bsdcan.org/2018/schedule/events/965.en.html .)
Submitted by: Michio Honda <micchie at sfc.wide.ad.jp> (previous version)
Reviewed by: lstewart (previous version)
Differential Revision: https://reviews.freebsd.org/D15706
Turns out there is code which ends up passing M_ZERO to counters.
Since counters zero unconditionally on their own, just ignore drop the
flag in that place.
pmc_process_interrupt takes 5 arguments when only 3 are needed.
cpu is always available in curcpu and inuserspace can always be
derived from the passed trapframe.
While facially a reasonable cleanup this change was motivated
by the need to workaround a compiler bug.
core2_intr(cpu, tf) ->
pmc_process_interrupt(cpu, ring, pmc, tf, inuserspace) ->
pmc_add_sample(cpu, ring, pm, tf, inuserspace)
In the process of optimizing the tail call the tf pointer was getting
clobbered:
(kgdb) up
at /storage/mmacy/devel/freebsd/sys/dev/hwpmc/hwpmc_mod.c:4709
4709 pmc_save_kernel_callchain(ps->ps_pc,
(kgdb) up
1205 error = pmc_process_interrupt(cpu, PMC_HR, pm, tf,
resulting in a crash in pmc_save_kernel_callchain.
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent acknowledgment) where counting dup-acks is no longer done
instead time is used to knwo when to retransmit. (see the I-D)
- TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
to try not to take a retransmit time-out. (see the I-D)
- Burst mitigation using TCPHTPS
- PRR (partial rate reduction) see the RFC.
Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.
Note that any connection that does not support SACK will be kicked
back to the "default" base FreeBSD stack (currently known as "default").
To build this into your kernel you will need to enable in your
kernel:
makeoptions WITH_EXTRA_TCP_STACKS=1
options TCPHPTS
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15525
controller that tries to handle early invocations of the controller,
in other words, invocations before the expected end of the interval.
However, there were some calculation errors in this early invocation
case. Notably, if an early invocation occurred while the error was
negative, the derivative term was off by a large amount. One visible
effect of this error was that processes were being killed by the
virtual memory system's OOM killer when in fact there was plentiful
free memory.
Correct a couple minor errors in the sysctl descriptions, and apply
some style fixes.
Reviewed by: jeff, markj
This patch adds a new socket option, SO_REUSEPORT_LB, which allow multiple
programs or threads to bind to the same port and incoming connections will be
load balanced using a hash function.
Most of the code was copied from a similar patch for DragonflyBSD.
However, in DragonflyBSD, load balancing is a global on/off setting and can not
be set per socket. This patch allows for simultaneous use of both the current
SO_REUSEPORT and the new SO_REUSEPORT_LB options on the same system.
Required changes to structures:
Globally change so_options from 16 to 32 bit value to allow for more options.
Add hashtable in pcbinfo to hold all SO_REUSEPORT_LB sockets.
Limitations:
As DragonflyBSD, a load balance group is limited to 256 pcbs (256 programs or
threads sharing the same socket).
This is a substantially different contribution as compared to its original
incarnation at svn r332894 and reverted at svn r332967. Thanks to rwatson@
for the substantive feedback that is included in this commit.
Submitted by: Johannes Lundberg <johalun0@gmail.com>
Obtained from: DragonflyBSD
Relnotes: Yes
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D11003
This is needed to avoid a race between the VNASSERT() below, and another
thread updating the VI_FREE flag, on weakly-ordered architectures.
On a 72-thread POWER9, without this barrier a 'make -j72 buildworld' would
panic on the assert regularly.
It may be possible to use a weaker barrier, and I'll investigate that once
all stability issues are worked out on POWER9.
By logging all threads and processes 'pmc filter'
can now filter on process or thread name, relieving
the user of the burden of determining which tid or
pid was which when the sample was taken.
% pmc filter -T if_io_tqg -P nginx pmc.log pmc-iflib.log
% pmc filter -x -T idle pmc.log pmc-noidle.log