freebsd with flexible iflib nic queues
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Alexander Motin f58c851d32 Reduce taskq and context-switch cost of zio pipe
When doing a read from disk, ZFS creates 3 ZIO's: a zio_null(), the
logical zio_read(), and then a physical zio. Currently, each of these
results in a separate taskq_dispatch(zio_execute).

On high-read-iops workloads, this causes a significant performance
impact. By processing all 3 ZIO's in a single taskq entry, we reduce the
overhead on taskq locking and context switching.  We accomplish this by
allowing zio_done() to return a "next zio to execute" to zio_execute().

This results in a ~12% performance increase for random reads, from
96,000 iops to 108,000 iops (with recordsize=8k, on SSD's).

Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-59292
Closes #7736

zfsonlinux/zfs@62840030a7
2018-08-03 02:16:45 +00:00
bin Describe how to prevent *.core files from being created using ulimit. 2018-07-19 13:09:29 +00:00
cddl MFV r337223: 2018-08-03 01:52:25 +00:00
contrib libelf: reload section headers after update with ELF_C_WRITE 2018-08-01 15:55:14 +00:00
crypto Merge upstream patch to unbreak tunnel forwarding. 2018-05-16 14:04:39 +00:00
etc Move pkg/FreeBSD.conf to usr.sbin/pkg/ 2018-07-31 16:42:03 +00:00
gnu Update libstdc++ configuration. 2018-07-16 18:53:28 +00:00
include msun: add ld80/ld128 powl, cpow, cpowf, cpowl from openbsd 2018-07-15 00:23:10 +00:00
kerberos5 Remove redundant space. 2018-07-10 00:26:13 +00:00
lib 9580 Add a hash-table on top of nvlist to speed-up operations 2018-08-03 01:37:14 +00:00
libexec Save and restore floating-point arguments. 2018-08-02 12:21:39 +00:00
release Fix the ftp-stage target for arm embedded builds. 2018-08-02 18:51:44 +00:00
rescue Avoid referencing private lib names directly. 2017-11-10 07:53:02 +00:00
sbin Make timespecadd(3) and friends public 2018-07-30 15:46:40 +00:00
secure Upgrade to OpenSSH 7.7p1. 2018-05-11 13:22:43 +00:00
share Update dirdeps.mk et al to latest 2018-08-02 21:33:45 +00:00
stand loader.efi: efipart_inithandles() failure should not prevent devsw initialization 2018-08-02 12:43:40 +00:00
sys Reduce taskq and context-switch cost of zio pipe 2018-08-03 02:16:45 +00:00
targets Remove special cases for armeb in the build. 2018-07-17 23:23:54 +00:00
tests Fix LOCAL_PEERCRED with socketpair(2) 2018-08-03 01:37:00 +00:00
tools tools: Add a git-svn bootstrap script 2018-08-02 18:28:02 +00:00
usr.bin wc(1): Fix 'wc -L' 2018-08-02 23:45:14 +00:00
usr.sbin bhyve: set title before entering capability mode 2018-08-02 21:54:34 +00:00
.arcconfig
.arclint arc lint: ignore /tests/ in chmod 2017-12-19 03:38:06 +00:00
.gitattributes Remove spuriously added svn properties 2018-08-02 18:37:02 +00:00
.gitignore Ignore _.universe-toolchain file. 2018-07-01 13:50:37 +00:00
COPYRIGHT Remove 'All Rights Reserved' from the collection copyright and templates. 2018-05-09 02:02:49 +00:00
LOCKS LOCKS: update current locks 2018-06-09 03:08:04 +00:00
MAINTAINERS Add pointer to freebsd-numerics for libm. 2018-07-16 15:29:32 +00:00
Makefile As discussed several times on freebsd-arch, start to decommission armeb. 2018-07-17 23:23:34 +00:00
Makefile.inc1 Alpha-sort the list of user/group IDs to check at install time. 2018-07-22 16:51:11 +00:00
Makefile.libcompat Makefile.libcompat: correctly append to make variable 2018-07-30 14:42:59 +00:00
Makefile.sys.inc AUTO_OBJ: For all top-level targets enforce using an OBJDIR. 2017-12-05 21:29:47 +00:00
ObsoleteFiles.inc Add a few forgotten files to ObsoleteFiles.inc: 2018-07-25 17:14:05 +00:00
README README: add generic notes about GENERIC and NOTES 2018-06-17 19:44:24 +00:00
README.md README: add generic notes about GENERIC and NOTES 2018-06-17 19:44:24 +00:00
UPDATING Remove jedec_ts(4) 2018-08-01 08:24:34 +00:00

FreeBSD Source:

This is the top level of the FreeBSD source directory. This file was last revised on: FreeBSD

FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.

For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.

The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.

Source Roadmap:

bin		System/user commands.

cddl		Various commands and libraries under the Common Development
		and Distribution License.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

stand		Boot loader sources.

sys		Kernel sources.

sys/<arch>/conf Kernel configuration files. GENERIC is the configuration
		used in release builds. NOTES contains documentation of
		all possible entries.

tests		Regression tests which can be run by Kyua.  See tests/README
		for additional information.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.

For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see:

https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/current-stable.html