On (23/01/15 13:21), Sergey Senozhatsky wrote: > On (23/01/14 13:34), Mike Kravetz wrote: > > I did the following: > > > > - Start with clean v6.2-rc3 > > Perform echo, did not see issue > > > > - Applied your 5 patches (includes the zsmalloc: turn chain size config option > > into UL constant patch). Took default value for ZSMALLOC_CHAIN_SIZE of 8. > > Performed echo, recreated issue. > > > > - Changed ZSMALLOC_CHAIN_SIZE to 1. > > Perform echo, did not see issue > > The patch set basically just adjusts $NUM in calculate_zspage_chain_size(): > > for (i = 1; i <= $NUM; i++) > > It changes default 4 to 8. Can't really see how this can cause problems. OK, I guess it overflows zspage isolated counter, which is a 3 bit integer, so the max chain-size we can have is b111 == 7. We probably need something like below (this should not increase sizeof zspage): --- diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 290053e648b0..86b742a613ee 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -129,7 +129,7 @@ #define HUGE_BITS 1 #define FULLNESS_BITS 2 #define CLASS_BITS 8 -#define ISOLATED_BITS 3 +#define ISOLATED_BITS 5 #define MAGIC_VAL_BITS 8 #define MAX(a, b) ((a) >= (b) ? (a) : (b))
