reside on their own cache line to prevent false sharing with other
nearby structures, especially for those in the .bss segment.
NB: Those mutexes and rwlocks with variables next to them that get
changed on every invocation do not benefit from their own cache line.
Actually it may be net negative because two cache misses would be
incurred in those cases.
connections in the accept queue and contiguous new incoming SYNs.
Compared to the original submitters patch I've moved the test
next to the SYN handling to have it together in a logical unit
and reworded the comment explaining the issue.
Submitted by: Matt Miller <matt@matthewjmiller.net>
Submitted by: Juan Mojica <jmojica@gmail.com>
Reviewed by: Matt Miller (changes)
Tested by: pho
MFC after: 1 week
This theoretically allows a compiler to optimize (parts of) the array
away if unused.
While there, make the array size implicit and use a _Static_assert() to
ensure that the definition matches up with the number of elements in the
list.
for us_freecount.
This grows uma_slab_head on 32-bit arches, but growth isn't
significant. Taking kmem zones as example, only the 32 byte
zone is affected, ipers is reduced from 113 to 112.
In collaboration with: kib
with the MAP_ENTRY_VN_WRITECNT flag:
- Move the assertion that verifies the state of the v_writecount and
vnp.writecount, under the block where the object is locked.
- Check that the object type is OBJT_VNODE before asserting.
Reported by: avg
Reviewed by: alc
MFC after: 1 week
sys/dev/firewire/firewire.c:
- fw_xfer_unload(): Since we are about to free this xfer, call fw_tl_free()
to remove the xfer from its tlabel's list, if it has a tlabel.
- In every occasion when a xfer is removed from a tlabel's list, reset
xfer->tl to -1 while holding fc->tlabel_lock, so that the xfer isn't
mis-identified as belonging to a tlabel.
This doesn't fix all the use-after-free problems for M_FWMEM, but is an
incremental towards that goal.
Reviewed by: kan, sbruno
Sponsored by: Spectra Logic
per-page lock rather than vm_object lock, without any further overhead.
Make the formal switch.
Sponsored by: EMC / Isilon storage division
Reviewed by: alc
Tested by: pho
Convert 'struct ipstat' and 'struct tcpstat' to counter(9).
This speeds up IP forwarding at extreme packet rates, and
makes accounting more precise.
Sponsored by: Nginx, Inc.
Introduce counter(9) API, that implements fast and raceless counters,
provided (but not limited to) for gathering of statistical data.
See http://lists.freebsd.org/pipermail/freebsd-arch/2013-April/014204.html
for more details.
In collaboration with: kib
Reviewed by: luigi
Tested by: ae, ray
Sponsored by: Nginx, Inc.
These zones have slab size == sizeof(struct pcpu), but request from VM
enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such
zone would have a separate twin for each CPU in the system, and these twins
are at a distance of sizeof(struct pcpu) from each other. This magic value
of distance would allow us to make some optimizations later.
To address private item from a CPU simple arithmetics should be used:
item = (type *)((char *)base + sizeof(struct pcpu) * curcpu)
These arithmetics are available as zpcpu_get() macro in pcpu.h.
To introduce non-page size slabs a new field had been added to uma_keg
uk_slabsize. This shifted some frequently used fields of uma_keg to the
fourth cache line on amd64. To mitigate this pessimization, uma_keg fields
were a bit rearranged and least frequently used uk_name and uk_link moved
down to the fourth cache line. All other fields, that are dereferenced
frequently fit into first three cache lines.
Sponsored by: Nginx, Inc.
connection after it was accepted by the userland nfsd process but before
it was handled off to svc_vc_create() in the kernel, then svc_vc_create()
would see it as a new listen socket and try to listen on it leaving a
dangling reference to the socket. Instead, check for disconnected sockets
and treat them like a connected socket. The call to pru_getaddr() should
fail and cause svc_vc_create() to fail. Note that we need to lock the
socket to get a consistent snapshot of so_state since there is a window
in soisdisconnected() where both flags are clear.
Reviewed by: dfr, rmacklem
MFC after: 1 week
relearning. Specifically, add subcommands to mfiutil(8) which allow the
user to set the BBU and autolearn modes when the firmware supports it,
and add a subcommand which kicks off a battery relearn.
Reviewed by: sbruno, rstone
Tested by: sbruno
Approved by: rstone (co-mentor)
MFC after: 2 weeks
Sponsored by: Sandvine Incorporated
the LUN was never freed.
ctl.c: Adjust ctl_alloc_lun() to make sure we don't clear the
CTL_LUN_MALLOCED flag.
Reported by: Sreenivasa Honnur <shonnur@chelsio.com>
Sponsored by: Spectra Logic
MFC after: 3 days
In r249041, I2C slave addresses were left-shifted at creation time to
have the same behavior between i915 and radeon (not committed yet). This
change broke the aux channel. The user-visible change was that display
port on i915 didn't work anymore.
To fix this, we right-shift the address back to restore the original value.
Reported by: Olivier Cochard-Labbé <olivier@cochard.me>
Tested by: Olivier Cochard-Labbé <olivier@cochard.me>
Reviewed by: kib@
Although native word padding (i.e. 8-byte on 64bit arch) looks to be
in agreement with standards, other parts of our code and other OSes
use 4-byte alignment.
This is not expected to change alignment for currently generated core
dump notes, as the notes look to consist of structures with sizes
multiple of 8 on 64-bit archs. But there are plans to add additional
notes, where 4-byte vs 8-byte alignment makes difference.
Discussed with: kib
Reviewed by: kib
MFC after: 2 weeks
POSIX mqueue, compatibility ksem and POSIX shm create a file descriptor that
has close-on-exec set. However, they do this incorrectly, leaving a window
where a thread may fork and exec while the flag has not been set yet. The
race is easily reproduced on a multicore system with one thread doing
shm_open and close and another thread doing posix_spawnp and waitpid.
Set UF_EXCLOSE via falloc()'s flags argument instead. This also simplifies
the code.
MFC after: 1 week
(ARM uses 'int' and 'unsigned'; i386 uses 'long' and 'unsigned long'),
so we need explicit casts to long and unsigned long here to ensure
that the result matches the printf %ld and %lx specifiers.
arrange for all of the fields to start at a short offset from the
beginning of the structure.
Eliminate unnecessary masking of VM_RADIX_FLAGS from the root pointer in
vm_radix_getroot().
Sponsored by: EMC / Isilon Storage Division
- Don't insert BKGRDMARKER bufs into the splay or dirty/clean buf lists.
No consumers need to find them there and it complicates the tree.
These flags are all FFS specific and could be moved out of the buf
cache.
- Use pbgetvp() and pbrelvp() to associate the background and journal
bufs with the vp. Not only is this much cheaper it makes more sense
for these transient bufs.
- Fix the assertions in pbget* and pbrel*. It's not safe to check list
pointers which were never initialized. Use the BX flags instead. We
also check B_PAGING in reassignbuf() so this should cover all cases.
Discussed with: kib, mckusick, attilio
Sponsored by: EMC / Isilon Storage Division
option left but actually consumed by ada(4), so move it to opt_ada.h
and get rid of opt_ata.h.
- Fix stand-alone build of atacore(4) by adding opt_cam.h.
- Use __FBSDID.
- Use DEVMETHOD_END.
- Use NULL instead of 0 for pointers.
Do not list read-only pools in zpool.cache
Reduce diff against vendor in unused vdev_disk.c
Illumos ZFS issues:
3639 zpool.cache should skip over readonly pools
3640 want automatic devid updates
MFC after: 1 week
- Move ata_timeout() to ata-all.c so we don't need to expose both this
function and ata_cam_end_transaction() but only the former.
- Move ata_cmd2str() from ata-queue.c to ata-all.c so we can get rid of
the former.
- Add some missing prototypes.
MFC after: 3 days
Merge change from vendor to reduce diff only.
ZFS dtrace probes are not supported on FreeBSD yet.
Illumos ZFS issues:
3598 want to dtrace when errors are generated in zfs
MFC after: 3 weeks
