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Filename Latest commit message Latest commit date
Davidlohr Bueso 679abf381a fs/eventpoll.c: loosen irq safety in ep_poll()
Similar to other calls, ep_poll() is not called with interrupts disabled,
and we can therefore avoid the irq save/restore dance and just disable
local irqs.  In fact, the call should never be called in irq context at
all, considering that the only path is

epoll_wait(2) -> do_epoll_wait() -> ep_poll().

When running on a 2 socket 40-core (ht) IvyBridge a common pipe based
epoll_wait(2) microbenchmark, the following performance improvements are
seen:

    # threads       vanilla         dirty
	 1          1805587	    2106412
	 2          1854064	    2090762
	 4          1805484	    2017436
	 8          1751222	    1974475
	 16         1725299	    1962104
	 32         1378463	    1571233
	 64          787368	     900784

Which is a pretty constantly near 15%.

Also add a lockdep check such that we detect any mischief before
deadlocking.

Link: http://lkml.kernel.org/r/20180727053432.16679-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
arch module: use relative references for __ksymtab entries 2018-08-22 10:52:47 -07:00
block
certs
crypto
Documentation kernel/hung_task.c: allow to set checking interval separately from timeout 2018-08-22 10:52:47 -07:00
drivers bcache: use routines from lib/crc64.c for CRC64 calculation 2018-08-22 10:52:48 -07:00
firmware
fs fs/eventpoll.c: loosen irq safety in ep_poll() 2018-08-22 10:52:49 -07:00
include lib: add crc64 calculation routines 2018-08-22 10:52:48 -07:00
init init: allow initcall tables to be emitted using relative references 2018-08-22 10:52:47 -07:00
ipc
kernel sched/wait: assert the wait_queue_head lock is held in __wake_up_common 2018-08-22 10:52:47 -07:00
lib lib/test_hexdump.c: fix failure on big endian cpu 2018-08-22 10:52:48 -07:00
LICENSES
mm bdi: use irqsave variant of refcount_dec_and_lock() 2018-08-22 10:52:46 -07:00
net The main things are support for cephx v2 authentication protocol and 2018-08-20 18:26:55 -07:00
samples
scripts checkpatch: DT bindings should be a separate patch 2018-08-22 10:52:49 -07:00
security init: allow initcall tables to be emitted using relative references 2018-08-22 10:52:47 -07:00
sound
tools proc: test /proc/thread-self symlink 2018-08-22 10:52:45 -07:00
usr
virt mm, oom: distinguish blockable mode for mmu notifiers 2018-08-22 10:52:44 -07:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS - New Drivers 2018-08-20 15:38:44 -07:00
Makefile Updates for v4.19: 2018-08-20 18:32:00 -07:00
README

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.
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.