From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8111AC2BBD5 for ; Thu, 17 Dec 2020 01:13:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48BB022D6E for ; Thu, 17 Dec 2020 01:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389082AbgLQBNH (ORCPT ); Wed, 16 Dec 2020 20:13:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:55110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389016AbgLQBMx (ORCPT ); Wed, 16 Dec 2020 20:12:53 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FCBF23AFA; Thu, 17 Dec 2020 01:05:04 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1kphj5-000xu0-8u; Wed, 16 Dec 2020 20:05:03 -0500 Message-ID: <20201217010503.108121702@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 16 Dec 2020 20:04:15 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Arnd Bergmann , Lukas Bulwahn , Masami Hiramatsu , Qiujun Huang Subject: [for-linus][PATCH 7/9] ring-buffer: Add rb_check_bpage in __rb_allocate_pages References: <20201217010408.742794078@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Qiujun Huang It may be better to check each page is aligned by 4 bytes. The 2 least significant bits of the address will be used as flags. Link: https://lkml.kernel.org/r/20201015113842.2921-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ring_buffer.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index e97ecf72c727..e03bc4e5d482 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1423,7 +1423,8 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) return 0; } -static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) +static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, + long nr_pages, struct list_head *pages) { struct buffer_page *bpage, *tmp; bool user_thread = current->mm != NULL; @@ -1463,13 +1464,15 @@ static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) struct page *page; bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), - mflags, cpu_to_node(cpu)); + mflags, cpu_to_node(cpu_buffer->cpu)); if (!bpage) goto free_pages; + rb_check_bpage(cpu_buffer, bpage); + list_add(&bpage->list, pages); - page = alloc_pages_node(cpu_to_node(cpu), mflags, 0); + page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), mflags, 0); if (!page) goto free_pages; bpage->page = page_address(page); @@ -1501,7 +1504,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, WARN_ON(!nr_pages); - if (__rb_allocate_pages(nr_pages, &pages, cpu_buffer->cpu)) + if (__rb_allocate_pages(cpu_buffer, nr_pages, &pages)) return -ENOMEM; /* @@ -2008,8 +2011,8 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, * allocated without receiving ENOMEM */ INIT_LIST_HEAD(&cpu_buffer->new_pages); - if (__rb_allocate_pages(cpu_buffer->nr_pages_to_update, - &cpu_buffer->new_pages, cpu)) { + if (__rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update, + &cpu_buffer->new_pages)) { /* not enough memory for new pages */ err = -ENOMEM; goto out_err; @@ -2074,8 +2077,8 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, INIT_LIST_HEAD(&cpu_buffer->new_pages); if (cpu_buffer->nr_pages_to_update > 0 && - __rb_allocate_pages(cpu_buffer->nr_pages_to_update, - &cpu_buffer->new_pages, cpu_id)) { + __rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update, + &cpu_buffer->new_pages)) { err = -ENOMEM; goto out_err; } -- 2.29.2