No description
Find a file
Chris Mason 08635bae0b Btrfs: stop using btrfs_schedule_bio()
btrfs_schedule_bio() hands IO off to a helper thread to do the actual
submit_bio() call.  This has been used to make sure async crc and
compression helpers don't get stuck on IO submission.  To maintain good
performance, over time the IO submission threads duplicated some IO
scheduler characteristics such as high and low priority IOs and they
also made some ugly assumptions about request allocation batch sizes.

All of this cost at least one extra context switch during IO submission,
and doesn't fit well with the modern blkmq IO stack.  So, this commit stops
using btrfs_schedule_bio().  We may need to adjust the number of async
helper threads for crcs and compression, but long term it's a better
path.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:52 +01:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-16 16:10:59 -08:00
block iocost: check active_list of all the ancestors in iocg_activate() 2019-11-14 13:56:54 -07:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-12 10:53:24 -08:00
drivers Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2019-11-17 08:15:41 -08:00
fs Btrfs: stop using btrfs_schedule_bio() 2019-11-18 12:46:52 +01:00
include btrfs: get rid of pointless wtag variable in async-thread.c 2019-11-18 12:46:49 +01:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-17 08:30:38 -08:00
lib lib/xz: fix XZ_DYNALLOC to avoid useless memory reallocations 2019-11-15 18:34:00 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/debug.c: PageAnon() is true for PageKsm() pages 2019-11-15 18:34:00 -08:00
net ipmr: Fix skb headroom in ipmr_get_route(). 2019-11-16 13:06:54 -08:00
samples samples/bpf: fix build by setting HAVE_ATTR_TEST to zero 2019-10-31 21:39:15 +01:00
scripts arm64 fix for -rc8 / final 2019-11-15 09:14:23 -08:00
security efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN 2019-10-31 09:40:21 +01:00
sound ALSA: usb-audio: Fix incorrect size check for processing/extension units 2019-11-14 18:01:22 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-16 15:52:00 -08:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM: Add a comment describing the /dev/kvm no_compat handling 2019-11-15 10:14:04 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS IOMMU Fixes for Linux v5.4-rc7 2019-11-17 11:27:44 -08:00
Makefile Linux 5.4-rc8 2019-11-17 14:47:30 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.