From patchwork Mon Jan 23 17:37:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13112703 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 252BEC38142 for ; Mon, 23 Jan 2023 18:06:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233808AbjAWSGP (ORCPT ); Mon, 23 Jan 2023 13:06:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233763AbjAWSGN (ORCPT ); Mon, 23 Jan 2023 13:06:13 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BDED30E95 for ; Mon, 23 Jan 2023 10:05:45 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 530B85616BDB; Mon, 23 Jan 2023 09:37:56 -0800 (PST) From: Stefan Roesch To: linux-mm@kvack.org Cc: shr@devkernel.io, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [RESEND RFC PATCH v1 05/20] mm: support disabling of ksm for a process Date: Mon, 23 Jan 2023 09:37:33 -0800 Message-Id: <20230123173748.1734238-6-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230123173748.1734238-1-shr@devkernel.io> References: <20230123173748.1734238-1-shr@devkernel.io> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This adds the ability to disable ksm for a process if ksm has been enabled for the process. Signed-off-by: Stefan Roesch --- mm/ksm.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/mm/ksm.c b/mm/ksm.c index 967eda719fab..5fa6b46dfa3b 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2588,6 +2588,27 @@ int __ksm_enter(struct mm_struct *mm, int flag) return 0; } +static void unmerge_vmas(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + struct vma_iterator vmi; + + vma_iter_init(&vmi, mm, 0); + + mmap_read_lock(mm); + for_each_vma(vmi, vma) { + if (vma->vm_flags & VM_MERGEABLE) { + unsigned long flags = vma->vm_flags; + + if (ksm_madvise(vma, vma->vm_start, vma->vm_end, MADV_UNMERGEABLE, &flags)) + continue; + + vma->vm_flags = flags; + } + } + mmap_read_unlock(mm); +} + void __ksm_exit(struct mm_struct *mm, int flag) { struct ksm_mm_slot *mm_slot; @@ -2595,8 +2616,10 @@ void __ksm_exit(struct mm_struct *mm, int flag) int easy_to_free = 0; if (!(current->flags & PF_EXITING) && flag == MMF_VM_MERGE_ANY && - test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + test_bit(MMF_VM_MERGE_ANY, &mm->flags)) { clear_bit(MMF_VM_MERGE_ANY, &mm->flags); + unmerge_vmas(mm); + } /* * This process is exiting: if it's straightforward (as is the