From patchwork Mon Jan 23 17:37:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13112682 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 8447AC38142 for ; Mon, 23 Jan 2023 17:59:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233094AbjAWR7n (ORCPT ); Mon, 23 Jan 2023 12:59:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233082AbjAWR7m (ORCPT ); Mon, 23 Jan 2023 12:59:42 -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 C56962ED7E for ; Mon, 23 Jan 2023 09:59:40 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 45FC35616BD5; 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 02/20] mm: add flag to __ksm_enter Date: Mon, 23 Jan 2023 09:37:30 -0800 Message-Id: <20230123173748.1734238-3-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-trace-kernel@vger.kernel.org This change adds the flag parameter to __ksm_enter. This allows to distinguish if ksm was called by prctl or madvise. Signed-off-by: Stefan Roesch --- include/linux/ksm.h | 6 ++++-- mm/ksm.c | 9 +++++---- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 7e232ba59b86..50e6b56092f3 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -18,13 +18,15 @@ #ifdef CONFIG_KSM int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags); -int __ksm_enter(struct mm_struct *mm); void __ksm_exit(struct mm_struct *mm); +int __ksm_enter(struct mm_struct *mm, int flag); static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) { + if (test_bit(MMF_VM_MERGE_ANY, &oldmm->flags)) + return __ksm_enter(mm, MMF_VM_MERGE_ANY); if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags)) - return __ksm_enter(mm); + return __ksm_enter(mm, MMF_VM_MERGEABLE); return 0; } diff --git a/mm/ksm.c b/mm/ksm.c index dd02780c387f..d84a244fe224 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2493,8 +2493,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, return 0; #endif - if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { - err = __ksm_enter(mm); + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags) && + !test_bit(MMF_VM_MERGE_ANY, &mm->flags)) { + err = __ksm_enter(mm, MMF_VM_MERGEABLE); if (err) return err; } @@ -2520,7 +2521,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, } EXPORT_SYMBOL_GPL(ksm_madvise); -int __ksm_enter(struct mm_struct *mm) +int __ksm_enter(struct mm_struct *mm, int flag) { struct ksm_mm_slot *mm_slot; struct mm_slot *slot; @@ -2553,7 +2554,7 @@ int __ksm_enter(struct mm_struct *mm) list_add_tail(&slot->mm_node, &ksm_scan.mm_slot->slot.mm_node); spin_unlock(&ksm_mmlist_lock); - set_bit(MMF_VM_MERGEABLE, &mm->flags); + set_bit(flag, &mm->flags); mmgrab(mm); if (needs_wakeup)