From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761845Ab3JPUQp (ORCPT ); Wed, 16 Oct 2013 16:16:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35924 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761822Ab3JPUQo (ORCPT ); Wed, 16 Oct 2013 16:16:44 -0400 Date: Wed, 16 Oct 2013 22:09:45 +0200 From: Oleg Nesterov To: Peter Zijlstra , Ingo Molnar Cc: linux-kernel@vger.kernel.org Subject: [PATCH 1/2] perf: Kill the dead !vma->vm_mm code in perf_event_mmap_event() Message-ID: <20131016200945.GB23214@redhat.com> References: <20131012192203.GA21738@redhat.com> <20131014102426.GX3081@twins.programming.kicks-ass.net> <20131016200924.GA23214@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131016200924.GA23214@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 1. perf_event_mmap(vma) is never called with a gate_vma-like arg, remove the "if (!vma->vm_mm)" code. 2. arch_vma_name() can use the chached value of mmap_event->vma. 3. Change the code to not call arch_vma_name() twice. 4. Purely cosmetic, but since we use "goto got_name" all the time remove "else" from "[stack]" branch just for symmetry. Signed-off-by: Oleg Nesterov --- kernel/events/core.c | 14 ++++++-------- 1 files changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index cb4238e..e27d8f8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5130,21 +5130,19 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) min = MINOR(dev); } else { - if (arch_vma_name(mmap_event->vma)) { - name = strncpy(tmp, arch_vma_name(mmap_event->vma), - sizeof(tmp) - 1); + name = arch_vma_name(vma); + if (name) { + name = strncpy(tmp, name, sizeof(tmp) - 1); tmp[sizeof(tmp) - 1] = '\0'; goto got_name; } - if (!vma->vm_mm) { - name = strncpy(tmp, "[vdso]", sizeof(tmp)); - goto got_name; - } else if (vma->vm_start <= vma->vm_mm->start_brk && + if (vma->vm_start <= vma->vm_mm->start_brk && vma->vm_end >= vma->vm_mm->brk) { name = strncpy(tmp, "[heap]", sizeof(tmp)); goto got_name; - } else if (vma->vm_start <= vma->vm_mm->start_stack && + } + if (vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack) { name = strncpy(tmp, "[stack]", sizeof(tmp)); goto got_name; -- 1.5.5.1