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Huang Ying 9c1cc2e4f2 mm, swap: fix comment in __read_swap_cache_async
Commit cbab0e4eec ("swap: avoid read_swap_cache_async() race to
deadlock while waiting on discard I/O completion") fixed a deadlock in
read_swap_cache_async().  Because at that time, in swap allocation path,
a swap entry may be set as SWAP_HAS_CACHE, then wait for discarding to
complete before the page for the swap entry is added to the swap cache.

But in commit 815c2c543d ("swap: make swap discard async"), the
discarding for swap become asynchronous, waiting for discarding to
complete will be done before the swap entry is set as SWAP_HAS_CACHE.
So the comments in code is incorrect now.  This patch fixes the
comments.

The cond_resched() added in the commit cbab0e4eec is not necessary now
too.  But if we added some sleep in swap allocation path in the future,
there may be some hard to debug/reproduce deadlock bug.  So it is kept.

Link: http://lkml.kernel.org/r/20170317064635.12792-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03 15:52:10 -07:00
arch blackfin: bf609: let clk_disable() return immediately if clk is NULL 2017-05-03 15:52:07 -07:00
block A reasonably busy cycle for documentation this time around. There is a new 2017-05-02 10:21:17 -07:00
certs KEYS: Use structure to capture key restriction function and data 2017-04-04 14:10:10 -07:00
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
Documentation mm: memcontrol: provide shmem statistics 2017-05-03 15:52:08 -07:00
drivers Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs jbd2: make the whole kjournald2 kthread NOFS safe 2017-05-03 15:52:09 -07:00
include mm: remove SWAP_[SUCCESS|AGAIN|FAIL] 2017-05-03 15:52:10 -07:00
init Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2017-05-02 19:09:35 -07:00
ipc kernel-api.rst: fix a series of errors when parsing C files 2017-04-02 14:31:49 -06:00
kernel mm: introduce memalloc_nofs_{save,restore} API 2017-05-03 15:52:09 -07:00
lib lockdep: allow to disable reclaim lockup detection 2017-05-03 15:52:09 -07:00
mm mm, swap: fix comment in __read_swap_cache_async 2017-05-03 15:52:10 -07:00
net Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit 2017-05-03 09:21:59 -07:00
samples Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2017-05-02 18:24:16 -07:00
scripts scripts/spelling.txt: add several more common spelling mistakes 2017-05-03 15:52:07 -07:00
security Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
sound LED updates for 4.12 2017-05-01 13:12:49 -07:00
tools Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2017-05-02 19:09:35 -07:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM Fixes for v4.11-rc6 2017-04-05 16:27:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add Martin Kepplinger's email 2017-04-13 18:24:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2017-05-02 19:09:35 -07:00
Makefile A reasonably busy cycle for documentation this time around. There is a new 2017-05-02 10:21:17 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.