Re: [PATCH] mm/mempool: warn about __GFP_ZERO usage

2014-04-16 Thread Andrew Morton
On Wed, 16 Apr 2014 14:15:56 -0700 Andrew Morton wrote: > @@ -201,7 +201,9 @@ void * mempool_alloc(mempool_t *pool, gf > wait_queue_t wait; > gfp_t gfp_temp; > > - VM_BUG_ON(gfp_mask & __GFP_ZERO); > +#ifdef CONFIG_DEBUG_VM > + WARN_ON_ONCE(gfp_mask & __GFP_ZERO);/* Whe

Re: [PATCH] mm/mempool: warn about __GFP_ZERO usage

2014-04-16 Thread Andrew Morton
On Mon, 14 Apr 2014 19:23:34 +0200 (CEST) Sebastian Ott wrote: > Memory obtained via mempool_alloc is not always zeroed even when > called with __GFP_ZERO. Add a note and VM_BUG_ON statement to make > that clear. > > .. > > @@ -200,6 +201,7 @@ void * mempool_alloc(mempool_t *pool, gf > wa

[PATCH] mm/mempool: warn about __GFP_ZERO usage

2014-04-14 Thread Sebastian Ott
Hello, I recently found out the hard way, that using mempool_alloc together with __GFP_ZERO is not a good idea since memory which comes from the pool of preallocated elemtents is not zeroed. Fixing this doesn't seem to be trivial since mempool is not aware of the size of the objects it manages. L