From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932453Ab1GEMyV (ORCPT ); Tue, 5 Jul 2011 08:54:21 -0400 Received: from hera.kernel.org ([140.211.167.34]:58478 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932106Ab1GEMyU (ORCPT ); Tue, 5 Jul 2011 08:54:20 -0400 Date: Tue, 5 Jul 2011 12:54:11 GMT From: tip-bot for Vaibhav Nagarnaik Message-ID: Cc: linux-kernel@vger.kernel.org, vnagarnaik@google.com, hpa@zytor.com, mingo@redhat.com, dhsharp@google.com, fweisbec@gmail.com, rostedt@goodmis.org, mrubin@google.com, tglx@linutronix.de, rientjes@google.com Reply-To: mingo@redhat.com, hpa@zytor.com, vnagarnaik@google.com, linux-kernel@vger.kernel.org, dhsharp@google.com, fweisbec@gmail.com, rostedt@goodmis.org, mrubin@google.com, tglx@linutronix.de, rientjes@google.com In-Reply-To: <1307491302-9236-1-git-send-email-vnagarnaik@google.com> References: <1307491302-9236-1-git-send-email-vnagarnaik@google.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] ring-buffer: Set __GFP_NORETRY flag for ring buffer allocating process Git-Commit-ID: d7ec4bfed6c97405c6417970ba06c439e08ab8e3 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 05 Jul 2011 12:54:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: d7ec4bfed6c97405c6417970ba06c439e08ab8e3 Gitweb: http://git.kernel.org/tip/d7ec4bfed6c97405c6417970ba06c439e08ab8e3 Author: Vaibhav Nagarnaik AuthorDate: Tue, 7 Jun 2011 17:01:42 -0700 Committer: Steven Rostedt CommitDate: Tue, 14 Jun 2011 22:48:51 -0400 ring-buffer: Set __GFP_NORETRY flag for ring buffer allocating process 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;