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Filename Latest commit message Latest commit date
Michal Hocko 71ab6cfe88 mm, vmscan: consider eligible zones in get_scan_count
get_scan_count() considers the whole node LRU size when

 - doing SCAN_FILE due to many page cache inactive pages
 - calculating the number of pages to scan

In both cases this might lead to unexpected behavior especially on 32b
systems where we can expect lowmem memory pressure very often.

A large highmem zone can easily distort SCAN_FILE heuristic because
there might be only few file pages from the eligible zones on the node
lru and we would still enforce file lru scanning which can lead to
trashing while we could still scan anonymous pages.

The later use of lruvec_lru_size can be problematic as well.  Especially
when there are not many pages from the eligible zones.  We would have to
skip over many pages to find anything to reclaim but shrink_node_memcg
would only reduce the remaining number to scan by SWAP_CLUSTER_MAX at
maximum.  Therefore we can end up going over a large LRU many times
without actually having chance to reclaim much if anything at all.  The
closer we are out of memory on lowmem zone the worse the problem will
be.

Fix this by filtering out all the ineligible zones when calculating the
lru size for both paths and consider only sc->reclaim_idx zones.

The patch would need to be tweaked a bit to apply to 4.10 and older but
I will do that as soon as it hits the Linus tree in the next merge
window.

Link: http://lkml.kernel.org/r/20170117103702.28542-3-mhocko@kernel.org
Fixes: b2e18757f2 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Tested-by: Trevor Cordes <trevor@tecnopolis.ca>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22 16:41:30 -08:00
arch powerpc: do not make the entire heap executable 2017-02-22 16:41:29 -08:00
block block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get() 2017-02-22 16:41:27 -08:00
certs
crypto crypto: algif_aead - Fix kernel panic on list_del 2017-02-03 17:45:48 +08:00
Documentation mm, thp: add new defer+madvise defrag option 2017-02-22 16:41:30 -08:00
drivers mm, dax: change pmd_fault() to take only vmf parameter 2017-02-22 16:41:26 -08:00
firmware
fs powerpc: do not make the entire heap executable 2017-02-22 16:41:29 -08:00
include mm, vmscan: cleanup lru size claculations 2017-02-22 16:41:30 -08:00
init slub: make sysfs directories for memcg sub-caches optional 2017-02-22 16:41:27 -08:00
ipc
kernel userfaultfd: non-cooperative: Add fork() event 2017-02-22 16:41:28 -08:00
lib dma-debug: add comment for failed to check map error 2017-02-22 16:41:26 -08:00
mm mm, vmscan: consider eligible zones in get_scan_count 2017-02-22 16:41:30 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
scripts scripts/tags.sh: include arch/Kconfig* for tags generation 2017-02-22 16:41:26 -08:00
security driver core patches for 4.11-rc1 2017-02-22 11:44:32 -08:00
sound ALSA: hda - adding a new NV HDMI/DP codec ID in the driver 2017-02-09 08:57:47 +01:00
tools userfaultfd: selftest: test UFFDIO_ZEROPAGE on all memory types 2017-02-22 16:41:29 -08:00
usr
virt KVM/ARM updates for 4.10-rc4 2017-01-17 15:04:59 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild
Kconfig
MAINTAINERS dax: update MAINTAINERS entries for FS DAX 2017-02-22 16:41:26 -08:00
Makefile Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 12:21:13 -08:00
README

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.