From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH 07/18] mm, proc: make clear_refs killable Date: Mon, 29 Feb 2016 18:38:45 +0100 Message-ID: <20160229173845.GC3615@redhat.com> References: <1456752417-9626-1-git-send-email-mhocko@kernel.org> <1456752417-9626-8-git-send-email-mhocko@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35205 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752750AbcB2Riy (ORCPT ); Mon, 29 Feb 2016 12:38:54 -0500 Content-Disposition: inline In-Reply-To: <1456752417-9626-8-git-send-email-mhocko@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Michal Hocko Cc: LKML , Andrew Morton , linux-mm@kvack.org, Alex Deucher , Alex Thorlton , Andrea Arcangeli , Andy Lutomirski , Benjamin LaHaise , Christian =?iso-8859-1?Q?K=F6nig?= , Daniel Vetter , Dave Hansen , David Airlie , Davidlohr Bueso , David Rientjes , "H . Peter Anvin" , Hugh Dickins , Ingo Molnar , Johannes Weiner , "Kirill A . Shutemov" , Konstantin Khlebnikov , linux-arch@vger.kernel.org, Mel Gorman , Peter Zijlstra On 02/29, Michal Hocko wrote: > > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1027,11 +1027,15 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, > }; > > if (type == CLEAR_REFS_MM_HIWATER_RSS) { > + if (down_write_killable(&mm->mmap_sem)) { > + put_task_struct(task); > + return -EINTR; > + } > + > /* > * Writing 5 to /proc/pid/clear_refs resets the peak > * resident set size to this mm's current rss value. > */ > - down_write(&mm->mmap_sem); > reset_mm_hiwater_rss(mm); > up_write(&mm->mmap_sem); > goto out_mm; > @@ -1043,7 +1047,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, > if (!(vma->vm_flags & VM_SOFTDIRTY)) > continue; > up_read(&mm->mmap_sem); > - down_write(&mm->mmap_sem); > + if (down_write_killable(&mm->mmap_sem)) { > + put_task_struct(task); > + return -EINTR; > + } Both lack mmput() afaics. Don't you need "goto out_mm" rather then "return" ? In this case you do not need put_task_struct(). Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:35205 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752750AbcB2Riy (ORCPT ); Mon, 29 Feb 2016 12:38:54 -0500 Date: Mon, 29 Feb 2016 18:38:45 +0100 From: Oleg Nesterov Subject: Re: [PATCH 07/18] mm, proc: make clear_refs killable Message-ID: <20160229173845.GC3615@redhat.com> References: <1456752417-9626-1-git-send-email-mhocko@kernel.org> <1456752417-9626-8-git-send-email-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456752417-9626-8-git-send-email-mhocko@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Michal Hocko Cc: LKML , Andrew Morton , linux-mm@kvack.org, Alex Deucher , Alex Thorlton , Andrea Arcangeli , Andy Lutomirski , Benjamin LaHaise , Christian =?iso-8859-1?Q?K=F6nig?= , Daniel Vetter , Dave Hansen , David Airlie , Davidlohr Bueso , David Rientjes , "H . Peter Anvin" , Hugh Dickins , Ingo Molnar , Johannes Weiner , "Kirill A . Shutemov" , Konstantin Khlebnikov , linux-arch@vger.kernel.org, Mel Gorman , Peter Zijlstra , Petr Cermak , Thomas Gleixner , Michal Hocko Message-ID: <20160229173845.ybSpxLn596IfiAZN2eYfnf4TuKe8kNogcSISFcBbqNw@z> On 02/29, Michal Hocko wrote: > > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1027,11 +1027,15 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, > }; > > if (type == CLEAR_REFS_MM_HIWATER_RSS) { > + if (down_write_killable(&mm->mmap_sem)) { > + put_task_struct(task); > + return -EINTR; > + } > + > /* > * Writing 5 to /proc/pid/clear_refs resets the peak > * resident set size to this mm's current rss value. > */ > - down_write(&mm->mmap_sem); > reset_mm_hiwater_rss(mm); > up_write(&mm->mmap_sem); > goto out_mm; > @@ -1043,7 +1047,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, > if (!(vma->vm_flags & VM_SOFTDIRTY)) > continue; > up_read(&mm->mmap_sem); > - down_write(&mm->mmap_sem); > + if (down_write_killable(&mm->mmap_sem)) { > + put_task_struct(task); > + return -EINTR; > + } Both lack mmput() afaics. Don't you need "goto out_mm" rather then "return" ? In this case you do not need put_task_struct(). Oleg.