From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id A0C036B0338 for ; Mon, 5 Oct 2015 09:28:44 -0400 (EDT) Received: by pablk4 with SMTP id lk4so176592662pab.3 for ; Mon, 05 Oct 2015 06:28:44 -0700 (PDT) Received: from m50-134.163.com (m50-134.163.com. [123.125.50.134]) by mx.google.com with ESMTP id cr7si40327179pad.107.2015.10.05.06.28.41 for ; Mon, 05 Oct 2015 06:28:43 -0700 (PDT) From: Geliang Tang Subject: [PATCH v2 3/3] mm/nommu: drop unlikely behind BUG_ON() Date: Mon, 5 Oct 2015 21:26:06 +0800 Message-Id: <4f765364227f9cdb0e837b165afe24ceb895548f.1444051018.git.geliangtang@163.com> In-Reply-To: <482d18783d6df356809b67431de95addfa20aa79.1444051018.git.geliangtang@163.com> References: <482d18783d6df356809b67431de95addfa20aa79.1444051018.git.geliangtang@163.com> In-Reply-To: <6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com> References: <482d18783d6df356809b67431de95addfa20aa79.1444051018.git.geliangtang@163.com> <6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , "Kirill A. Shutemov" , Hugh Dickins , "Peter Zijlstra (Intel)" , Andrea Arcangeli , Davidlohr Bueso , Joonsoo Kim , Paul Gortmaker , Leon Romanovsky , Oleg Nesterov Cc: Geliang Tang , linux-mm@kvack.org, linux-kernel@vger.kernel.org (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless[1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang Acked-by: Davidlohr Bueso --- Changes in v2: - Just rewrite the commit log. --- mm/nommu.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 1e0f168..92be862 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -578,16 +578,16 @@ static noinline void validate_nommu_regions(void) return; last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(last->vm_end <= last->vm_start)); - BUG_ON(unlikely(last->vm_top < last->vm_end)); + BUG_ON(last->vm_end <= last->vm_start); + BUG_ON(last->vm_top < last->vm_end); while ((p = rb_next(lastp))) { region = rb_entry(p, struct vm_region, vm_rb); last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(region->vm_end <= region->vm_start)); - BUG_ON(unlikely(region->vm_top < region->vm_end)); - BUG_ON(unlikely(region->vm_start < last->vm_top)); + BUG_ON(region->vm_end <= region->vm_start); + BUG_ON(region->vm_top < region->vm_end); + BUG_ON(region->vm_start < last->vm_top); lastp = p; } -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org