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Nadav Amit 756398750e resource: avoid unnecessary lookups in find_next_iomem_res()
find_next_iomem_res() shows up to be a source for overhead in dax
benchmarks.

Improve performance by not considering children of the tree if the top
level does not match.  Since the range of the parents should include the
range of the children such check is redundant.

Running sysbench on dax (pmem emulation, with write_cache disabled):

  sysbench fileio --file-total-size=3G --file-test-mode=rndwr \
   --file-io-mode=mmap --threads=4 --file-fsync-mode=fdatasync run

Provides the following results:

		events (avg/stddev)
		-------------------
  5.2-rc3:	1247669.0000/16075.39
  w/patch:	1286320.5000/16402.72	(+3%)

Link: http://lkml.kernel.org/r/20190613045903.4922-3-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:06 -07:00
Documentation mm: thp: fix false negative of shmem vma's THP eligibility 2019-07-18 17:08:06 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE 2019-07-18 17:08:06 -07:00
block docs conversion for v5.3-rc1 2019-07-16 12:21:41 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
drivers mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail 2019-07-18 17:08:06 -07:00
fs mm: thp: fix false negative of shmem vma's THP eligibility 2019-07-18 17:08:06 -07:00
include mm: thp: make transhuge_vma_suitable available for anonymous THP 2019-07-18 17:08:06 -07:00
init Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
ipc ipc/mqueue.c: only perform resource calculation if user valid 2019-07-16 19:23:24 -07:00
kernel resource: avoid unnecessary lookups in find_next_iomem_res() 2019-07-18 17:08:06 -07:00
lib Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
mm mm: thp: fix false negative of shmem vma's THP eligibility 2019-07-18 17:08:06 -07:00
net pci-v5.3-changes 2019-07-15 20:44:49 -07:00
samples VFIO updates for v5.3-rc1 2019-07-17 11:23:13 -07:00
scripts Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
security docs conversion for v5.3-rc1 2019-07-16 12:21:41 -07:00
sound sound fixes for 5.3-rc1 2019-07-18 09:36:51 -07:00
tools Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
usr docs: early-userspace: move to driver-api guide 2019-07-15 11:03:01 -03:00
virt ARM: 2019-07-12 15:35:14 -07:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 .gitignore: exclude .get_maintainer.ignore and .gitattributes 2019-05-18 11:49:54 +09:00
.mailmap MAINTAINERS: Update my email address 2019-06-18 14:37:27 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS docs: admin-guide: move sysctl directory to it 2019-07-15 11:03:01 -03:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS More power management updates for 5.3-rc1 2019-07-18 09:32:28 -07:00
Makefile Kbuild updates for v5.3 2019-07-12 16:03:16 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.

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.