From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934450AbcLTJ5s (ORCPT ); Tue, 20 Dec 2016 04:57:48 -0500 Received: from mail-wj0-f193.google.com ([209.85.210.193]:33083 "EHLO mail-wj0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932869AbcLTJ5l (ORCPT ); Tue, 20 Dec 2016 04:57:41 -0500 Date: Tue, 20 Dec 2016 10:57:38 +0100 From: Michal Hocko To: "Kirill A. Shutemov" Cc: Tetsuo Handa , Peter Zijlstra , Rik van Riel , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA Message-ID: <20161220095738.GD3769@dhcp22.suse.cz> References: <20161219171722.77995-1-kirill.shutemov@linux.intel.com> <20161219171722.77995-4-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161219171722.77995-4-kirill.shutemov@linux.intel.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 19-12-16 20:17:22, Kirill A. Shutemov wrote: > Logic on whether we can reap pages from the VMA should match what we > have in madvise_dontneed(). In particular, we should skip, VM_PFNMAP > VMAs, but we don't now. > > Let's just extract condition on which we can shoot down pagesi from a > VMA with MADV_DONTNEED into separate function and use it in both places. > > Signed-off-by: Kirill A. Shutemov you need to include internal.h in madvise.c diff --git a/mm/madvise.c b/mm/madvise.c index 20200dfbd1bb..c53d8da9c8e6 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -24,6 +24,8 @@ #include +#include "internal.h" + /* * Any behaviour which results in changes to the vma->vm_flags needs to * take mmap_sem for writing. Others, which simply traverse vmas, need otherwise it won't compile. Then you can add Acked-by: Michal Hocko > --- > mm/internal.h | 5 +++++ > mm/madvise.c | 2 +- > mm/oom_kill.c | 9 +-------- > 3 files changed, 7 insertions(+), 9 deletions(-) > > diff --git a/mm/internal.h b/mm/internal.h > index 44d68895a9b9..7430628bff34 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -41,6 +41,11 @@ int do_swap_page(struct vm_fault *vmf); > void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, > unsigned long floor, unsigned long ceiling); > > +static inline bool can_madv_dontneed_vma(struct vm_area_struct *vma) > +{ > + return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)); > +} > + > void unmap_page_range(struct mmu_gather *tlb, > struct vm_area_struct *vma, > unsigned long addr, unsigned long end, > diff --git a/mm/madvise.c b/mm/madvise.c > index aa4c502caecb..20200dfbd1bb 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -473,7 +473,7 @@ static long madvise_dontneed(struct vm_area_struct *vma, > unsigned long start, unsigned long end) > { > *prev = vma; > - if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) > + if (!can_madv_dontneed_vma(vma)) > return -EINVAL; > > zap_page_range(vma, start, end - start); > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 96a53ab0c9eb..b6d8ac4948db 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -508,14 +508,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) > > tlb_gather_mmu(&tlb, mm, 0, -1); > for (vma = mm->mmap ; vma; vma = vma->vm_next) { > - if (is_vm_hugetlb_page(vma)) > - continue; > - > - /* > - * mlocked VMAs require explicit munlocking before unmap. > - * Let's keep it simple here and skip such VMAs. > - */ > - if (vma->vm_flags & VM_LOCKED) > + if (!can_madv_dontneed_vma(vma)) > continue; > > /* > -- > 2.10.2 > -- Michal Hocko SUSE Labs