Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752476AbZFVAna (ORCPT ); Sun, 21 Jun 2009 20:43:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751174AbZFVAnX (ORCPT ); Sun, 21 Jun 2009 20:43:23 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56375 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750996AbZFVAnW (ORCPT ); Sun, 21 Jun 2009 20:43:22 -0400 Message-ID: <4A3ED40E.6030303@cn.fujitsu.com> Date: Mon, 22 Jun 2009 08:45:02 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Liming Wang CC: Steven Rostedt , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ftrace: don't increment @pos in g_start() References: <4A3B347B.8090904@cn.fujitsu.com> <1245401968-25235-1-git-send-email-liming.wang@windriver.com> <4A3B5E40.8040607@cn.fujitsu.com> In-Reply-To: <4A3B5E40.8040607@cn.fujitsu.com> Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2086 Lines: 76 Li Zefan wrote: > Liming Wang wrote: >> how about this one? >> > > Yeah, this should work, and cleaner than my version. > Hmmm, the patch is cleaner in diffstat but the resulted code isn't.. After yours: text data bss dec hex filename 14879 5480 4240 24599 6017 kernel/trace/ftrace.o After mine: text data bss dec hex filename 14873 5480 4240 24593 6011 kernel/trace/ftrace.o >> It's wrong to increment @pos in g_start(). It causes some entries >> lost when reading set_graph_function, if the output of the file >> is large than PAGE_SIZE. >> >> [ Impact: fix missing entries when reading set_graph_function ] >> >> Signed-off-by: Li Zefan >> Signed-off-by: Liming Wang >> --- >> kernel/trace/ftrace.c | 14 +++++--------- >> 1 files changed, 5 insertions(+), 9 deletions(-) >> >> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c >> index 134e580..1beaac6 100644 >> --- a/kernel/trace/ftrace.c >> +++ b/kernel/trace/ftrace.c >> @@ -2495,29 +2495,25 @@ static void * >> g_next(struct seq_file *m, void *v, loff_t *pos) >> { >> unsigned long *array = m->private; >> - int index = *pos; >> >> - (*pos)++; >> + if (v) >> + (*pos)++; >> >> - if (index >= ftrace_graph_count) >> + if (*pos >= ftrace_graph_count) >> return NULL; >> >> - return &array[index]; >> + return &array[*pos]; >> } >> >> static void *g_start(struct seq_file *m, loff_t *pos) >> { >> - void *p = NULL; >> - >> mutex_lock(&graph_lock); >> >> /* Nothing, tell g_show to print all functions are enabled */ >> if (!ftrace_graph_count && !*pos) >> return (void *)1; >> >> - p = g_next(m, p, pos); >> - >> - return p; >> + return g_next(m, NULL, pos); >> } >> >> static void g_stop(struct seq_file *m, void *p) -- 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/