From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id B7DE06B0005 for ; Sun, 7 Apr 2013 09:49:49 -0400 (EDT) Received: by mail-wi0-f176.google.com with SMTP id hm14so1823617wib.3 for ; Sun, 07 Apr 2013 06:49:48 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1365326292-2761-1-git-send-email-k80ck80c@gmail.com> References: <1365326292-2761-1-git-send-email-k80ck80c@gmail.com> Date: Sun, 7 Apr 2013 21:49:47 +0800 Message-ID: Subject: Re: [PATCH 1/1] mmap.c: find_vma: eliminate initial if(mm) check From: Yanfei Zhang Content-Type: multipart/alternative; boundary=089e01227b94f3c3b004d9c59779 Sender: owner-linux-mm@kvack.org List-ID: To: k80c Cc: Andrew Morton , Michel Lespinasse , Rik van Riel , Al Viro , Ingo Molnar , linux-mm@kvack.org, linux-kernel@vger.kernel.org --089e01227b94f3c3b004d9c59779 Content-Type: text/plain; charset=UTF-8 I've sent the same patch and has been merged into -mm tree by Andrew Morton. Thanks Zhang 2013/4/7 k80c > As per commit 841e31e5cc6219d62054788faa289b6ed682d068, > we dont really need this if(mm) check anymore. > > A WARN_ON_ONCE was added just for safety, but there have been no bug > reports about this so far. > > Removing this if(mm) check. > > Signed-off-by: k80c > --- > mm/mmap.c | 3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 0db0de1..b2c363f 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1935,9 +1935,6 @@ struct vm_area_struct *find_vma(struct mm_struct > *mm, unsigned long addr) > { > struct vm_area_struct *vma = NULL; > > - if (WARN_ON_ONCE(!mm)) /* Remove this in linux-3.6 */ > - return NULL; > - > /* Check the cache first. */ > /* (Cache hit rate is typically around 35%.) */ > vma = ACCESS_ONCE(mm->mmap_cache); > -- > 1.7.5.4 > > -- > 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/ > --089e01227b94f3c3b004d9c59779 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I've sent the same patch and has been merged into -mm tree by Andr= ew Morton.
=C2=A0
Thanks
Zhang

<= div class=3D"gmail_quote">2013/4/7 k80c <k80ck80c@gmail.com>
As per commit 841e31e5cc6219d62054788faa289b6ed682d068, we dont really need this if(mm) check anymore.

A WARN_ON_ONCE was added just for safety, but there have been no bug
reports about this so far.

Removing this if(mm) check.

Signed-off-by: k80c <k80ck80c@gmai= l.com>
---
=C2=A0mm/mmap.c | =C2=A0 =C2=A03 ---
=C2=A01 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 0db0de1..b2c363f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1935,9 +1935,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm,= unsigned long addr)
=C2=A0{
=C2=A0 =C2=A0 =C2=A0 =C2=A0 struct vm_area_struct *vma =3D NULL;

- =C2=A0 =C2=A0 =C2=A0 if (WARN_ON_ONCE(!mm)) =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0/* Remove this in linux-3.6 */
- =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 return NULL;
-
=C2=A0 =C2=A0 =C2=A0 =C2=A0 /* Check the cache first. */
=C2=A0 =C2=A0 =C2=A0 =C2=A0 /* (Cache hit rate is typically around 35%.) */=
=C2=A0 =C2=A0 =C2=A0 =C2=A0 vma =3D ACCESS_ONCE(mm->mmap_cache);
--
1.7.5.4

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