diff options
author | Seth Jennings <sjenning@linux.vnet.ibm.com> | 2011-10-12 14:41:00 -0500 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-10-17 15:24:11 -0700 |
commit | 00bf256011d362e7d61824f3cda8514f5d48585d (patch) | |
tree | c76261e9e4d023628673253f74648504295274ed /drivers/staging/et131x | |
parent | 3b769edd58371fb70417c3f43c6d4a2da075703a (diff) |
staging: zcache: remove zcache_direct_reclaim_lock
zcache_do_preload() currently does a spin_trylock() on the
zcache_direct_reclaim_lock. Holding this lock intends to prevent
shrink_zcache_memory() from evicting zbud pages as a result
of a preload.
However, it also prevents two threads from
executing zcache_do_preload() at the same time. The first
thread will obtain the lock and the second thread's spin_trylock()
will fail (an aborted preload) causing the page to be either lost
(cleancache) or pushed out to the swap device (frontswap). It
also doesn't ensure that the call to shrink_zcache_memory() is
on the same thread as the call to zcache_do_preload().
Additional, there is no need for this mechanism because all
zcache_do_preload() calls that come down from cleancache already
have PF_MEMALLOC set in the process flags which prevents
direct reclaim in the memory manager. If the zcache_do_preload()
call is done from the frontswap path, we _want_ reclaim to be
done (which it isn't right now).
This patch removes the zcache_direct_reclaim_lock and related
statistics in zcache.
Based on v3.1-rc8
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Reviewed-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/et131x')
0 files changed, 0 insertions, 0 deletions