From 32c5fb7e7d18b4fd37c5e29dea731151e9d66866 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 16 Oct 2013 22:09:45 +0200 Subject: [PATCH] perf: Kill the dead !vma->vm_mm code in perf_event_mmap_event() 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 Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20131016200945.GB23214@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 028dad9..3ea5605 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5136,21 +5136,19 @@ 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; -- 2.7.4