[Devel] [PATCH RHEL7 COMMIT] tcache: do not populate on global reclaim

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-123.1.2-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-123.1.2.vz7.5.25
------>
commit a809936620eba145245ca60e494449623f3a38a1
Author: Vladimir Davydov <vdavydov at parallels.com>
Date:   Fri Jul 17 17:53:11 2015 +0400

    tcache: do not populate on global reclaim
    
    Just like in case of tswap, there is no point in populating tcache on
    global reclaim. It is not that dangerous though, because, in contrast to
    tswap, tcache reclaim drops pages instead of moving them back to page
    cache.
    
    Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
    Reviewed-by: Kirill Tkhai <ktkhai at odin.com>
---
 mm/tcache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/tcache.c b/mm/tcache.c
index 6c1e9e7..6499881 100644
--- a/mm/tcache.c
+++ b/mm/tcache.c
@@ -838,7 +838,7 @@ static void tcache_cleancache_put_page(int pool_id,
 
 	node = tcache_get_node_and_pool(pool_id, &key, true);
 	if (node) {
-		if (tcache_active)
+		if (tcache_active && !(current->flags & PF_MEMALLOC))
 			cache_page = tcache_alloc_page();
 		if (cache_page) {
 			copy_highpage(cache_page, page);