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author | Minchan Kim <minchan@kernel.org> | 2013-09-25 18:57:43 -0500 |
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committer | Simon Shields <keepcalm444@gmail.com> | 2016-06-12 21:20:21 +1000 |
commit | c72e09b31537cd8c558f70fd00d40c755e670114 (patch) | |
tree | 1f9782df9be80b6f0769aa89aa3b16a93c83fdb4 /kernel/mutex-debug.c | |
parent | 128faec612bd65b7c7b5318c47d35f4cabbc3060 (diff) | |
download | kernel_samsung_smdk4412-c72e09b31537cd8c558f70fd00d40c755e670114.zip kernel_samsung_smdk4412-c72e09b31537cd8c558f70fd00d40c755e670114.tar.gz kernel_samsung_smdk4412-c72e09b31537cd8c558f70fd00d40c755e670114.tar.bz2 |
mm: remove compressed copy from zram in-memory
Swap subsystem does lazy swap slot free with expecting the page would be
swapped out again so we can avoid unnecessary write.
But the problem in in-memory swap(ex, zram) is that it consumes memory
space until vm_swap_full(ie, used half of all of swap device) condition
meet. It could be bad if we use multiple swap device, small in-memory
swap and big storage swap or in-memory swap alone.
This patch makes swap subsystem free swap slot as soon as swap-read is
completed and make the swapcache page dirty so the page should be
written out the swap device to reclaim it. It means we never lose it.
I tested this patch with kernel compile workload.
1. before
compile time : 9882.42
zram max wasted space by fragmentation: 13471881 byte
memory space consumed by zram: 174227456 byte
the number of slot free notify: 206684
2. after
compile time : 9653.90
zram max wasted space by fragmentation: 11805932 byte
memory space consumed by zram: 154001408 byte
the number of slot free notify: 426972
[akpm@linux-foundation.org: tweak comment text]
[artem.savkov@gmail.com: fix BUG due to non-swapcache pages in end_swap_bio_read()]
[akpm@linux-foundation.org: invert unlikely() test, augment comment, 80-col cleanup]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Konrad Rzeszutek Wilk <konrad@darnok.org>
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I8f11fb7f0391954435002e7f290352f311c907d4
Signed-off-by: Paul Reioux <reioux@gmail.com>
Conflicts:
mm/page_io.c
Diffstat (limited to 'kernel/mutex-debug.c')
0 files changed, 0 insertions, 0 deletions