From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755356Ab1FON70 (ORCPT ); Wed, 15 Jun 2011 09:59:26 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:52239 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755177Ab1FON7V (ORCPT ); Wed, 15 Jun 2011 09:59:21 -0400 X-Authority-Analysis: v=1.1 cv=yMxAJ7W7nAoPh8ZdbvCArpG6pAdHwgpzIvOq8QbMesM= c=1 sm=0 a=vhdKIqpQuCYA:10 a=3IU65XaaRhcA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=1XWaLZrsAAAA:8 a=20KFwNOVAAAA:8 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=meVymXHHAAAA:8 a=8ptb5Uy6ivW2y5QcxncA:9 a=U9ctsTGuUy1NW2ajw4MA:7 a=UTB_XpHje0EA:10 a=jEp0ucaQiEUA:10 a=MSl-tDqOz04A:10 a=jeBq3FmKZ4MA:10 a=MbCQTi7IOFYeluSK:21 a=7aD7Ez85Ie4lI5iA:21 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110615135235.991241140@goodmis.org> User-Agent: quilt/0.48-1 Date: Wed, 15 Jun 2011 09:48:54 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu , David Rientjes , Vaibhav Nagarnaik , Ingo Molnar , Frederic Weisbecker , Michael Rubin , David Sharp Subject: [PATCH 13/16 v2] ring-buffer: Set __GFP_NORETRY flag for ring buffer allocating References: <20110615134841.767565350@goodmis.org> Content-Disposition: inline; filename=0013-ring-buffer-Set-__GFP_NORETRY-flag-for-ring-buffer-a.patch process Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vaibhav Nagarnaik The tracing ring buffer is allocated from kernel memory. While allocating a large chunk of memory, OOM might happen which destabilizes the system. Thus random processes might get killed during the allocation. This patch adds __GFP_NORETRY flag to the ring buffer allocation calls to make it fail more gracefully if the system will not be able to complete the allocation request. Acked-by: David Rientjes Signed-off-by: Vaibhav Nagarnaik Cc: Ingo Molnar Cc: Frederic Weisbecker Cc: Michael Rubin Cc: David Sharp Link: http://lkml.kernel.org/r/1307491302-9236-1-git-send-email-vnagarnaik@google.com Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 25 +++++++++++++++++++------ 1 files changed, 19 insertions(+), 6 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index f00ede3..731201b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1004,9 +1004,14 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, for (i = 0; i < nr_pages; i++) { struct page *page; - + /* + * __GFP_NORETRY flag makes sure that the allocation fails + * gracefully without invoking oom-killer and the system is + * not destabilized. + */ bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), - GFP_KERNEL, cpu_to_node(cpu_buffer->cpu)); + GFP_KERNEL | __GFP_NORETRY, + cpu_to_node(cpu_buffer->cpu)); if (!bpage) goto free_pages; @@ -1015,7 +1020,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, list_add(&bpage->list, &pages); page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), - GFP_KERNEL, 0); + GFP_KERNEL | __GFP_NORETRY, 0); if (!page) goto free_pages; bpage->page = page_address(page); @@ -1377,13 +1382,20 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) for_each_buffer_cpu(buffer, cpu) { for (i = 0; i < new_pages; i++) { struct page *page; + /* + * __GFP_NORETRY flag makes sure that the allocation + * fails gracefully without invoking oom-killer and + * the system is not destabilized. + */ bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), - GFP_KERNEL, cpu_to_node(cpu)); + GFP_KERNEL | __GFP_NORETRY, + cpu_to_node(cpu)); if (!bpage) goto free_pages; list_add(&bpage->list, &pages); - page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, 0); + page = alloc_pages_node(cpu_to_node(cpu), + GFP_KERNEL | __GFP_NORETRY, 0); if (!page) goto free_pages; bpage->page = page_address(page); @@ -3737,7 +3749,8 @@ void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu) struct buffer_data_page *bpage; struct page *page; - page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, 0); + page = alloc_pages_node(cpu_to_node(cpu), + GFP_KERNEL | __GFP_NORETRY, 0); if (!page) return NULL; -- 1.7.4.4