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Shaohua Li 3ef1c33f98 block-throttle: avoid double charge
commit 111be88398 upstream.

If a bio is throttled and split after throttling, the bio could be
resubmited and enters the throttling again. This will cause part of the
bio to be charged multiple times. If the cgroup has an IO limit, the
double charge will significantly harm the performance. The bio split
becomes quite common after arbitrary bio size change.

To fix this, we always set the BIO_THROTTLED flag if a bio is throttled.
If the bio is cloned/split, we copy the flag to new bio too to avoid a
double charge. However, cloned bio could be directed to a new disk,
keeping the flag be a problem. The observation is we always set new disk
for the bio in this case, so we can clear the flag in bio_set_dev().

This issue exists for a long time, arbitrary bio size change just makes
it worse, so this should go into stable at least since v4.2.

V1-> V2: Not add extra field in bio based on discussion with Tejun

Cc: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-12-29 17:53:47 +01:00
arch x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit 2017-12-29 17:53:45 +01:00
block block-throttle: avoid double charge 2017-12-29 17:53:47 +01:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto crypto: af_alg - fix race accessing cipher request 2017-12-29 17:53:46 +01:00
Documentation x86/cpu_entry_area: Move it out of the fixmap 2017-12-29 17:53:45 +01:00
drivers PCI / PM: Force devices to D0 in pci_pm_thaw_noirq() 2017-12-29 17:53:47 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-25 14:26:21 +01:00
include block-throttle: avoid double charge 2017-12-29 17:53:47 +01:00
init init: Invoke init_espfix_bsp() from mm_init() 2017-12-29 17:53:45 +01:00
ipc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernel arch, mm: Allow arch_dup_mmap() to fail 2017-12-29 17:53:43 +01:00
lib x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*' 2017-12-25 14:26:13 +01:00
mm mm/sparsemem: Fix ARM64 boot crash when CONFIG_SPARSEMEM_EXTREME=y 2017-12-25 14:26:31 +01:00
net Revert "ipv6: grab rt->rt6i_ref before allocating pcpu rt" 2017-12-29 17:53:41 +01:00
samples samples/bpf: adjust rlimit RLIMIT_MEMLOCK for xdp1 2017-12-20 10:10:31 +01:00
scripts linux/compiler.h: Split into compiler.h and compiler_types.h 2017-12-25 14:26:33 +01:00
security apparmor: fix leak of null profile name if profile allocation fails 2017-12-14 09:53:06 +01:00
sound ALSA: usb-audio: Fix the missing ctl name suffix at parsing SU 2017-12-29 17:53:47 +01:00
tools x86/ldt: Prevent LDT inheritance on exec 2017-12-29 17:53:43 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt kvm, mm: account kvm related kmem slabs to kmemcg 2017-12-25 14:26:25 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING [PATCH] update FSF address in COPYING 2005-09-10 10:06:29 -07:00
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2017-11-09 18:26:51 -08:00
Makefile Linux 4.14.9 2017-12-25 14:26:48 +01:00
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.