o Do not use UMA refcount zone. The problem with this zone is that
several refcounting words (16 on amd64) share the same cache line,
and issueing atomic(9) updates on them creates cache line contention.
Also, allocating and freeing them is extra CPU cycles.
Instead, refcount the page directly via vm_page_wire() and the sfbuf
via sf_buf_alloc(sf_buf_page(sf)) [1].
o Call refcounting/freeing function for EXT_SFBUF via direct function
call, instead of function pointer. This removes barrier for CPU
branch predictor.
o Do not cleanup the mbuf to be freed in mb_free_ext(), merely to
satisfy assertion in mb_dtor_mbuf(). Remove the assertion from
mb_dtor_mbuf(). Use bcopy() instead of manual assignments to
copy m_ext in mb_dupcl().
[1] This has some problems for now. Using sf_buf_alloc() merely to
increase refcount is expensive, and is broken on sparc64. To be
fixed.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
a source address was selected and cached, but it was not
stored that is was cached. This resulted in selecting
different source addresses for the INIT-ACK and COOKIE-ACK
when possible.
Thanks to Niu Zhixiong for reporting the issue.
MFC after: 1 week
Code trying to take a look has to check fd_refcnt and it is 0 by that time.
This is a follow up to r268505, without this the code would leak memory for
tables bigger than the default.
MFC after: 1 week
entry was being tested. We were incrementing and decrementing the pmap's
wired mapping count based on whether the physical page being mapped or
unmapped was cache coherent, not whether it was a wired mapping.
Reviewed by: nwhitehorn
The Tx interrupt is now kept disabled in the common case, only
enabled when the number of free descriptors in the queue falls
below a threshold. Transmitted frames are cleared from the VQ
before subsequent transmit, or in the watchdog timer.
This was a very big performance improvement for an experimental
Netmap bhyve backend.
MFC after: 1 month
awareness.
* Introduce IP_BINDMULTI - indicating that it's okay to bind multiple
sockets on the same bind details.
Although the PCB code has been taught about this (see below) this patch
doesn't introduce the rest of the PCB changes necessary to distribute
lookups among multiple PCB entries in the global wildcard table.
* Introduce IP_RSS_LISTEN_BUCKET - placing an listen socket into the
given RSS bucket (and thus a single PCBGROUP hash.)
* Modify the PCB add path to be aware of IP_BINDMULTI:
+ Only allow further PCB entries to be added if the owner credentials
and IP_BINDMULTI has been specified. Ie, only allow further
IP_BINDMULTI sockets to appear if the first bind() was IP_BINDMULTI.
* Teach the PCBGROUP code about IP_RSS_LISTE_BUCKET marked PCB entries.
Instead of using the wildcard logic and hashing, these sockets are
simply placed into the PCBGROUP and _not_ in the wildcard hash.
* When doing a PCBGROUP lookup, also do a wildcard match as well.
This allows for an RSS bucket PCB entry to appear in a PCBGROUP
rather than having to exist in the wildcard list.
Tested:
* TCP IPv4 server testing with igb(4)
* TCP IPv4 server testing with ix(4)
TODO:
* The pcbgroup lookup code duplicated the wildcard and wildcard-PCB
logic. This could be refactored into a single function.
* This doesn't yet work for IPv6 (The PCBGROUP code in netinet6/ doesn't
yet know about this); nor does it yet fully work for UDP.
percentage of machines has a 16550. Disable it for pc98 since only a
tiny fraction of them have one. These changes save 293 bytes when
building with clang, but preserves the ability to build with serial if
you really want. We now have 92 bytes free (412 with the in-tree gcc).
Use reserved space for ZFS administrative commands.
We reserve 1/2^spa_slop_shift = 1/32 or 3.125% of pool space (or 32MB at
least) for system use. Most ZPL operations, e.g. write(2), creat(2), will
fail with ENOSPC if we fall below this.
Certain operations, e.g. file removal and most administrative actions,
still permitted until half of the slop space is used. This would allow
users to use these operations to free up space in the pool when pool is
close to full but half of slop space is still free.
A very restricted set of operations that frees up space or change quota
are always permitted, regardless of the amount of free space.
MFC after: 2 weeks
ptrace_set_pc() use the correct return to userspace using iret.
The signal return, PT_CONTINUE (which in fact uses signal return path)
set the pcb flag already. The setcontext(2) enforces iret return when
%rip is incorrect. Due to this, the change is redundand, but is made
to ensure that no path which modifies context, forgets to set
PCB_FULL_IRET.
Inspired by: CVE-2014-4699
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
amount of resident pages, in fact calculates the amount of installed
pte entries in the region. Resident pages which were not soft-faulted
yet are not counted.
Calculate the amount of resident pages by looking in the objects chain
backing the region.
Add a knob to disable the residency calculation at all. For large
sparce regions, either previous or updated algorithm runs for too long
time, while several introspection tools do not need the (advisory) RSS
value at all.
PR: kern/188911
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Explicitly mark file removal transactions as "presumed to result
in a net free of space" so they will not fail with ENOSPC.
Illumos issue: 4950 files sometimes can't be removed from a full
filesystem
MFC after: 2 weeks
The number of vm fictitious regions was limited to 8 by default, but
Xen will make heavy usage of those kind of regions in order to map
memory from foreign domains, so instead of increasing the default
number, change the implementation to use a red-black tree to track vm
fictitious ranges.
The public interface remains the same.
Sponsored by: Citrix Systems R&D
Reviewed by: kib, alc
Approved by: gibbs
vm/vm_phys.c:
- Replace the vm fictitious static array with a red-black tree.
- Use a rwlock instead of a mutex, since now we also need to take the
lock in vm_phys_fictitious_to_vm_page, and it can be shared.
While it is possible to create and write file, modify its permissions, etc.
without ever doing sync, it looks odd that it is required for setting
extended file attributes on ZFS. UFS does not do sync there too.
Samba uses those extended attributes to store some its data, and doing it
synchronously by many times reduces file creation performance for systems
without SLOG device.
Reviewed by: delphij, jpaetzel, silence on fs@
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
That should make operation more kind to multi-initiator environment.
Without this, other initiators may find out that something bad happened
to their commands only via command timeout.
Testing shown that both original queued design with separate task queue,
and recent direct execution design had significant flaw: If abort request
arrives just after the victim, the last one may not be in the ooa_queue
yet, and so invisible for the task management function.
Unlike original queued implementation, use same queue for all SCSI and
TASK requests from the same initiator. That avoids races between them:
task functions are always executed in proper time, relatively to other
requests.
