IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
zbud_alloc() incorrectly verifies the size of allocation limit. It
should deny the allocation request greater than (PAGE_SIZE -
ZHDR_SIZE_ALIGNED - CHUNK_SIZE), not (PAGE_SIZE - ZHDR_SIZE_ALIGNED)
which has no remaining spaces for its buddy. There is no point in
spending the entire zbud page storing only a single page, since we don't
have any benefits.
Signed-off-by: Heesub Shin <heesub.shin@samsung.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Dongjun Shin <d.j.shin@samsung.com>
Cc: Sunae Seo <sunae.seo@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zbud is an special purpose allocator for storing compressed pages. It
is designed to store up to two compressed pages per physical page.
While this design limits storage density, it has simple and
deterministic reclaim properties that make it preferable to a higher
density approach when reclaim will be used.
zbud works by storing compressed pages, or "zpages", together in pairs
in a single memory page called a "zbud page". The first buddy is "left
justifed" at the beginning of the zbud page, and the last buddy is
"right justified" at the end of the zbud page. The benefit is that if
either buddy is freed, the freed buddy space, coalesced with whatever
slack space that existed between the buddies, results in the largest
possible free region within the zbud page.
zbud also provides an attractive lower bound on density. The ratio of
zpages to zbud pages can not be less than 1. This ensures that zbud can
never "do harm" by using more pages to store zpages than the
uncompressed zpages would have used on their own.
This implementation is a rewrite of the zbud allocator internally used
by zcache in the driver/staging tree. The rewrite was necessary to
remove some of the zcache specific elements that were ingrained
throughout and provide a generic allocation interface that can later be
used by zsmalloc and others.
This patch adds zbud to mm/ for later use by zswap.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Jenifer Hopper <jhopper@us.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
