zcache allocations happen during reclaim of pages,
and waking up kswapd at this time hinders system
performance. During tests it was seen that without
this patch, there were a lot of kswapd wakeups and
was resulting in bad launches.
Change-Id: Ic0f0240b8fdad6b3fe142b2bdc0366cfd870635e
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
zcache_pool_pages is supposed to store the total
pages in all the pools used by zcache. But at
present zcache_pool_pages is assigned pages of any
particular pool on a load, store or any operation
which modifies the pool size. And this is more
important for external clients which depend on zcache
pool size, like the lowmemorykiller.
Change-Id: Ifdaab8646c40f1fec71dfa5903658fbdc6b3cce5
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
When file pages drops down, at a point zcache pages
can be more than the file pages, and even further when
we have to reclaim the maximum number of file pages
possible to launch an application, we need a way to
reclaim even the zcache pages at least to an extend
which makes it match with the number of file pages.
This can help in better foreground headroom.
Change-Id: I481bfb9961ed5cee47ebeae08eb910bb269b644c
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
zcache store ops cannot sleep since it is called from
an atomic context. Pass the right flags to alloc functions.
Change-Id: I9c7956e895fb7909932315aa3d85845127aa02e1
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Implemented zbud_ops->evict, so that compressed zpages can be evicted from
zbud memory pool in the case that the compressed pool is full.
zbud already managered the compressed pool based on LRU. The evict was
implemented just by dropping the compressed file page data directly, if
the data is required again then no more disk reading can be saved.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Patch-mainline: linux-mm @ 2013-08-06 11:36:16
[vinmenon@codeaurora.org: trivial merge conflict fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: Ia66652475e490f0233547511e80abf7587054e65
zcache is a backend for cleancache that takes file pages that are in the
process of being reclaimed and attempts to compress them and store them
in a RAM-based memory pool. This can result in a significant I/O reduction
if system is full with file pages and, in the case where decompressing
from RAM is faster than reading from the disk, can also improve workload
performance.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Patch-mainline: linux-mm @ 2013-08-06 11:36:14
[vinmenon@codeaurora.org: trivial merge conflict fixes, checkpatch fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: Id05bcc1946eee22b94a83adeb0134a3f6e357ef8
