From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDCAA30EF69; Fri, 6 Mar 2026 12:17:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772799426; cv=none; b=PlGd14rqipZLUap+TQL04rBOhRsunhOtek6zP2dxqVHXpbPA609RCImU9ZPUMHtmwcVvmmxIyeL8xydRNScSQLv1hjZGavNG+49dythof+Ddyt15CovUW86Cc+m5EQa2f5DvHpZvC0WKzn4nmnHMNWysYi8kkXhIY2qWACsJyTE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772799426; c=relaxed/simple; bh=E50Nei4wvO5acKQ5WAuR9y8yrxBw8Jw9n6m//WAfpNk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=q/zM7BmZen2AAgjV9MHw8zTPQq1CNq5nrl1LFm+YHw28QJI/yCzktzGbmxVG8fYLoco8Xz8jI0ZDdckXesem9YSLxGeOUj9tCVtTMCz16wOMNne6rLwBOAT0oNzFuKnabGF4TDyYHmnO9Rtte/GMN6/IdI1aS5Fv2iqDRgRuuek= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JE9hl+xg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JE9hl+xg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9601AC4CEF7; Fri, 6 Mar 2026 12:17:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772799426; bh=E50Nei4wvO5acKQ5WAuR9y8yrxBw8Jw9n6m//WAfpNk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JE9hl+xgT0bTGi+BM5jUSHSxJhmfXyDYuZyy882H8pwaPVW4rs91GqXsOlDdNYt5q M4CYD21uXiIoE80aCpIXZWa8pvS6BpzRhby5F3zlbgDBohqfN8gLvqI1ZzEKj9Sq8O 1GA8U2yXsayzOcXwk/z9rDzRougLhaH2sFQZ/lImuHVanVDszwy6gcpcLHaEn0JF34 5MRb84nwU6hkVV8bxr42O43gDIOYuZx7PoAczRQyQjOzRXl+pydnhhFnDCu0OWdTD3 GeXNhxm0JknludP4ZgMHI0L5kkBWpm7KDg9wTx0PM6ikXJpjNR7e3ecgYQUbTFzh7m tM4T4pFHUGsng== Date: Fri, 6 Mar 2026 12:17:03 +0000 From: "Lorenzo Stoakes (Oracle)" To: "David Hildenbrand (Arm)" Cc: linux-kernel@vger.kernel.org, "linux-mm @ kvack . org" , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , David Rientjes , Shakeel Butt , "Matthew Wilcox (Oracle)" , Alice Ryhl , Madhavan Srinivasan , Michael Ellerman , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Greg Kroah-Hartman , Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , Todd Kjos , Christian Brauner , Carlos Llamas , Ian Abbott , H Hartley Sweeten , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Jason Gunthorpe , Leon Romanovsky , Dimitri Sivanich , Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Andy Lutomirski , Vincenzo Frascino , Eric Dumazet , Neal Cardwell , "David S. Miller" , David Ahern , Jakub Kicinski , Paolo Abeni , Miguel Ojeda , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-sgx@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, rust-for-linux@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v1 06/16] mm/oom_kill: factor out zapping of VMA into zap_vma_for_reaping() Message-ID: References: <20260227200848.114019-1-david@kernel.org> <20260227200848.114019-7-david@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260227200848.114019-7-david@kernel.org> On Fri, Feb 27, 2026 at 09:08:37PM +0100, David Hildenbrand (Arm) wrote: > Let's factor it out so we can turn unmap_page_range() into a static > function instead, and so oom reaping has a clean interface to call. > > Note that hugetlb is not supported, because it would require a bunch of > hugetlb-specific further actions (see zap_page_range_single_batched()). Ugh gawd. Hugetlb. > > Signed-off-by: David Hildenbrand (Arm) Seems reasonable, so: Reviewed-by: Lorenzo Stoakes (Oracle) > --- > mm/internal.h | 5 +---- > mm/memory.c | 36 ++++++++++++++++++++++++++++++++---- > mm/oom_kill.c | 15 +-------------- > 3 files changed, 34 insertions(+), 22 deletions(-) > > diff --git a/mm/internal.h b/mm/internal.h > index 39ab37bb0e1d..df9190f7db0e 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -536,13 +536,10 @@ static inline void sync_with_folio_pmd_zap(struct mm_struct *mm, pmd_t *pmdp) > } > > struct zap_details; > -void unmap_page_range(struct mmu_gather *tlb, > - struct vm_area_struct *vma, > - unsigned long addr, unsigned long end, > - struct zap_details *details); > void zap_page_range_single_batched(struct mmu_gather *tlb, > struct vm_area_struct *vma, unsigned long addr, > unsigned long size, struct zap_details *details); > +int zap_vma_for_reaping(struct vm_area_struct *vma); > int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio, > gfp_t gfp); > > diff --git a/mm/memory.c b/mm/memory.c > index e4154f03feac..621f38ae1425 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2054,10 +2054,9 @@ static inline unsigned long zap_p4d_range(struct mmu_gather *tlb, > return addr; > } > > -void unmap_page_range(struct mmu_gather *tlb, > - struct vm_area_struct *vma, > - unsigned long addr, unsigned long end, > - struct zap_details *details) > +static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, > + unsigned long addr, unsigned long end, > + struct zap_details *details) > { > pgd_t *pgd; > unsigned long next; > @@ -2115,6 +2114,35 @@ static void unmap_single_vma(struct mmu_gather *tlb, > } > } > > +/** > + * zap_vma_for_reaping - zap all page table entries in the vma without blocking > + * @vma: The vma to zap. > + * > + * Zap all page table entries in the vma without blocking for use by the oom > + * killer. Hugetlb vmas are not supported. > + * > + * Returns: 0 on success, -EBUSY if we would have to block. > + */ > +int zap_vma_for_reaping(struct vm_area_struct *vma) > +{ > + struct mmu_notifier_range range; > + struct mmu_gather tlb; > + > + VM_WARN_ON_ONCE(is_vm_hugetlb_page(vma)); > + > + mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, > + vma->vm_start, vma->vm_end); > + tlb_gather_mmu(&tlb, vma->vm_mm); > + if (mmu_notifier_invalidate_range_start_nonblock(&range)) { > + tlb_finish_mmu(&tlb); > + return -EBUSY; > + } > + unmap_page_range(&tlb, vma, range.start, range.end, NULL); > + mmu_notifier_invalidate_range_end(&range); > + tlb_finish_mmu(&tlb); > + return 0; > +} > + > /** > * unmap_vmas - unmap a range of memory covered by a list of vma's > * @tlb: address of the caller's struct mmu_gather > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 0ba56fcd10d5..54b7a8fe5136 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -548,21 +548,8 @@ static bool __oom_reap_task_mm(struct mm_struct *mm) > * count elevated without a good reason. > */ > if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) { > - struct mmu_notifier_range range; > - struct mmu_gather tlb; > - > - mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, > - mm, vma->vm_start, > - vma->vm_end); > - tlb_gather_mmu(&tlb, mm); > - if (mmu_notifier_invalidate_range_start_nonblock(&range)) { > - tlb_finish_mmu(&tlb); > + if (zap_vma_for_reaping(vma)) > ret = false; > - continue; > - } > - unmap_page_range(&tlb, vma, range.start, range.end, NULL); > - mmu_notifier_invalidate_range_end(&range); > - tlb_finish_mmu(&tlb); > } > } > > -- > 2.43.0 >