lkml.org 
[lkml]   [2012]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 04/16] mm: allow PF_MEMALLOC from softirq context
On Fri, Jun 22, 2012 at 03:30:31PM +0100, Mel Gorman wrote:
> This is needed to allow network softirq packet processing to make
> use of PF_MEMALLOC.

> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index b6c0727..5c6d9c6 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2265,7 +2265,11 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
> if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
> if (gfp_mask & __GFP_MEMALLOC)
> alloc_flags |= ALLOC_NO_WATERMARKS;
> - else if (likely(!(gfp_mask & __GFP_NOMEMALLOC)) && !in_interrupt())
> + else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
> + alloc_flags |= ALLOC_NO_WATERMARKS;
> + else if (!in_interrupt() &&
> + ((current->flags & PF_MEMALLOC) ||
> + unlikely(test_thread_flag(TIF_MEMDIE))))
> alloc_flags |= ALLOC_NO_WATERMARKS;
> }

You allocate in RX path with __GFP_MEMALLOC and your sk->sk_allocation has
also __GFP_MEMALLOC set. That means you should get ALLOC_NO_WATERMARKS in
alloc_flags. Is this to done to avoid GFP annotations in skb_share_check() and
friends on your __netif_receive_skb() path?

Sebastian


\
 
 \ /
  Last update: 2012-06-26 19:41    [W:0.292 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site