From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f43.google.com (mail-pb0-f43.google.com [209.85.160.43]) by kanga.kvack.org (Postfix) with ESMTP id 2C3776B004D for ; Wed, 2 Oct 2013 15:39:37 -0400 (EDT) Received: by mail-pb0-f43.google.com with SMTP id md4so1350519pbc.2 for ; Wed, 02 Oct 2013 12:39:36 -0700 (PDT) Date: Wed, 2 Oct 2013 21:39:33 +0200 From: Jan Kara Subject: Re: [PATCH 16/26] mm: Provide get_user_pages_unlocked() Message-ID: <20131002193933.GC16998@quack.suse.cz> References: <1380724087-13927-1-git-send-email-jack@suse.cz> <1380724087-13927-17-git-send-email-jack@suse.cz> <524C499B.9090707@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <524C499B.9090707@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: Jan Kara , LKML , linux-mm@kvack.org On Wed 02-10-13 12:28:11, KOSAKI Motohiro wrote: > (10/2/13 10:27 AM), Jan Kara wrote: > > Provide a wrapper for get_user_pages() which takes care of acquiring and > > releasing mmap_sem. Using this function reduces amount of places in > > which we deal with mmap_sem. > > > > Signed-off-by: Jan Kara > > --- > > include/linux/mm.h | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index 8b6e55ee8855..70031ead06a5 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -1031,6 +1031,20 @@ long get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > > struct vm_area_struct **vmas); > > int get_user_pages_fast(unsigned long start, int nr_pages, int write, > > struct page **pages); > > +static inline long > > +get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, > > + unsigned long start, unsigned long nr_pages, > > + int write, int force, struct page **pages) > > +{ > > + long ret; > > + > > + down_read(&mm->mmap_sem); > > + ret = get_user_pages(tsk, mm, start, nr_pages, write, force, pages, > > + NULL); > > + up_read(&mm->mmap_sem); > > + return ret; > > +} > > Hmmm. I like the idea, but I really dislike this name. I don't like xx_unlocked > function takes a lock. It is a source of confusing, I believe. Sure, I'm not very happy about the name either. As Christoph wrote probably renaming all get_user_pages() variants might be appropriate. I'll think about names some more. Honza -- Jan Kara SUSE Labs, CR -- 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