Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755699Ab0AVBSj (ORCPT ); Thu, 21 Jan 2010 20:18:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755577Ab0AVBSR (ORCPT ); Thu, 21 Jan 2010 20:18:17 -0500 Received: from mail-fx0-f220.google.com ([209.85.220.220]:53143 "EHLO mail-fx0-f220.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755252Ab0AVBQc (ORCPT ); Thu, 21 Jan 2010 20:16:32 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=YDA50xwQq/55QbBkCdQJjsYug5BW+pwXWi/LbYL5j1/jn4lvowDddNEJGgNRIMK3uG bvNcQ2Vdcr4zymzbunxYzApC9kGZ1vc82GOFgziOfZAEN6LGXB6cpWrYCPc+57PRW/RF 7sjnGYiWBu/XIn5E2X3/D2s5tQewygImn7fwQ= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Steven Rostedt , Li Zefan , Lai Jiangshan Subject: [RFC PATCH 05/10] ftrace: Drop buffer check in function profiler callbacks Date: Fri, 22 Jan 2010 02:16:17 +0100 Message-Id: <1264122982-1553-6-git-send-regression-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 In-Reply-To: <1264122982-1553-1-git-send-regression-fweisbec@gmail.com> References: <1264122982-1553-1-git-send-regression-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 55 Drop the null check on hlist->hash. It is wasteful because we don't register the tracer if the buffer allocation failed, and the memory barrier in register_ftrace_graph() ensure it is visible to the callbacks right away. Also we know the tracing callbacks won't be called after register_ftrace_graph(), so subsequent buffer resets are safe too. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Li Zefan Cc: Lai Jiangshan --- kernel/trace/ftrace.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 3cdb35e..dfd8f7c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -384,8 +384,6 @@ function_profile_call(unsigned long ip, unsigned long parent_ip) local_irq_save(flags); hlist = &__get_cpu_var(func_hlist_cpu); - if (!hlist->hash) - goto out; rec = function_find_hlist_node(hlist, ip); if (!rec) { @@ -415,8 +413,6 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) local_irq_save(flags); hlist = &__get_cpu_var(func_hlist_cpu); - if (!hlist->hash) - goto out; calltime = trace->rettime - trace->calltime; @@ -439,7 +435,6 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) if (rec) rec->time += calltime; - out: local_irq_restore(flags); } -- 1.6.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/