forked from Minki/linux
00bf256011
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> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| tmem.c | ||
| tmem.h | ||
| zcache-main.c | ||