From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx137.postini.com [74.125.245.137]) by kanga.kvack.org (Postfix) with SMTP id C45976B006C for ; Tue, 4 Sep 2012 03:32:03 -0400 (EDT) Received: by wgbdq12 with SMTP id dq12so4150630wgb.26 for ; Tue, 04 Sep 2012 00:32:02 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1344955130-29478-1-git-send-email-elezegarcia@gmail.com> References: <1344955130-29478-1-git-send-email-elezegarcia@gmail.com> Date: Tue, 4 Sep 2012 10:32:02 +0300 Message-ID: Subject: Re: [PATCH 1/2] mm, slob: Prevent false positive trace upon allocation failure From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Ezequiel Garcia Cc: linux-mm@kvack.org, Christoph Lameter , Glauber Costa Hi Ezequiel, On Tue, Aug 14, 2012 at 5:38 PM, Ezequiel Garcia wrote: > This patch changes the __kmalloc_node() logic to return NULL > if alloc_pages() fails to return valid pages. > This is done to avoid to trace a false positive kmalloc event. > > Cc: Pekka Enberg > Cc: Christoph Lameter > Cc: Glauber Costa > Signed-off-by: Ezequiel Garcia > --- > mm/slob.c | 11 ++++++----- > 1 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/mm/slob.c b/mm/slob.c > index 45d4ca7..686e98b 100644 > --- a/mm/slob.c > +++ b/mm/slob.c > @@ -450,15 +450,16 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node) > size, size + align, gfp, node); > } else { > unsigned int order = get_order(size); > + struct page *page; > > if (likely(order)) > gfp |= __GFP_COMP; > ret = slob_new_pages(gfp, order, node); > - if (ret) { > - struct page *page; > - page = virt_to_page(ret); > - page->private = size; > - } > + if (!ret) > + return NULL; > + > + page = virt_to_page(ret); > + page->private = size; > > trace_kmalloc_node(_RET_IP_, ret, > size, PAGE_SIZE << order, gfp, node); As mentioned earlier, I think it's valuable for the userspace to be able to trace allocation failures as well. So I'm not applying this patch. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org