X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2FDocumentation%2Fvm%2Fbalance;h=964595481af683a7a9c344182ca707fd1c2a33fa;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=c46e68cf93449aadb652bdce92953c53bb00ca22;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/Documentation/vm/balance b/kernel/Documentation/vm/balance
index c46e68cf9..964595481 100644
--- a/kernel/Documentation/vm/balance
+++ b/kernel/Documentation/vm/balance
@@ -1,12 +1,14 @@
 Started Jan 2000 by Kanoj Sarcar <kanoj@sgi.com>
 
-Memory balancing is needed for non __GFP_WAIT as well as for non
-__GFP_IO allocations.
+Memory balancing is needed for !__GFP_ATOMIC and !__GFP_KSWAPD_RECLAIM as
+well as for non __GFP_IO allocations.
 
-There are two reasons to be requesting non __GFP_WAIT allocations:
-the caller can not sleep (typically intr context), or does not want
-to incur cost overheads of page stealing and possible swap io for
-whatever reasons.
+The first reason why a caller may avoid reclaim is that the caller can not
+sleep due to holding a spinlock or is in interrupt context. The second may
+be that the caller is willing to fail the allocation without incurring the
+overhead of page reclaim. This may happen for opportunistic high-order
+allocation requests that have order-0 fallback options. In such cases,
+the caller may also wish to avoid waking kswapd.
 
 __GFP_IO allocation requests are made to prevent file system deadlocks.