From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A39DC106F2F4 for ; Thu, 26 Mar 2026 08:08:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9FAD16B0095; Thu, 26 Mar 2026 04:08:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 95D266B0096; Thu, 26 Mar 2026 04:08:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 825996B0098; Thu, 26 Mar 2026 04:08:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 6D8556B0095 for ; Thu, 26 Mar 2026 04:08:53 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 39330E0DD5 for ; Thu, 26 Mar 2026 08:08:53 +0000 (UTC) X-FDA: 84587488146.29.92B226C Received: from mail-dl1-f73.google.com (mail-dl1-f73.google.com [74.125.82.73]) by imf04.hostedemail.com (Postfix) with ESMTP id 47A7040002 for ; Thu, 26 Mar 2026 08:08:51 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20251104 header.b=fjtAn8K3; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf04.hostedemail.com: domain of 3kenEaQYKCMwAC9w5ty66y3w.u64305CF-442Dsu2.69y@flex--surenb.bounces.google.com designates 74.125.82.73 as permitted sender) smtp.mailfrom=3kenEaQYKCMwAC9w5ty66y3w.u64305CF-442Dsu2.69y@flex--surenb.bounces.google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1774512531; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PUqdYCoBg/kEy42eZkJV8irdcP7MA2fDPdgYAg1G1X4=; b=Gaw0Q4KXByuSpbv+UH5Wy71WyfJG0GAQQfHPstJHPIpWwthaEo5+SsS1r5Cb5AIes3coCh ToVtV94GX4s4ARzgnPQbPIcpe/+3SRS0+zdONDgM7wqgqmAItKBb9ytzJ0WhAJP9o23toJ zv/A9BLy9+3L2+o/mRNI/6b20yp9nzg= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1774512531; a=rsa-sha256; cv=none; b=VyFxFIkk3Nn4PHU7zhcbIkjZLJpNbeRhrgm2Wpre65KFX2szTUVV6Qd9/ZjpWfrV8XQycv rCWxdSzrJedli2vrWg99h/CzZtGh1tpPiA19igb5wGJt5zlG733WGibN78lDdpVYYoqmJt Km2CPCgStHzMyBcM6UNDoBFPQcbz7ik= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20251104 header.b=fjtAn8K3; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf04.hostedemail.com: domain of 3kenEaQYKCMwAC9w5ty66y3w.u64305CF-442Dsu2.69y@flex--surenb.bounces.google.com designates 74.125.82.73 as permitted sender) smtp.mailfrom=3kenEaQYKCMwAC9w5ty66y3w.u64305CF-442Dsu2.69y@flex--surenb.bounces.google.com Received: by mail-dl1-f73.google.com with SMTP id a92af1059eb24-12711ec96fbso3104827c88.0 for ; Thu, 26 Mar 2026 01:08:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1774512530; x=1775117330; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=PUqdYCoBg/kEy42eZkJV8irdcP7MA2fDPdgYAg1G1X4=; b=fjtAn8K3BdRfSioZtUZ6HzyU3M65uZOgC0iPPoI5aWdAwxpHO3R1emEC7EUhdgGE9e NLXmEeqiBB1WOgiJyxJ7z/pCGZSqYaUB5RjhtjxnW/Vn3g4dUq//ZjvcaGcXqAkbofGr 3CtX6bruUg+0IQr8xbPrJeNvl0ko27BqSczjdQJjcps89/GrxN7DcmxDkc0QWZK9VX58 omGMftM4oByNgYVLqxTbOVdkytE9t7ow9bXVuxxhZm57D1e4P/jn2L9Vc2F54W0NC5FV OfNW8Z+uK0IKeEIQ4x9RQMxl5o6ju2btxqHwdjP3QefuKxCT2XnaFGVWxUT3Fyc9ZB1T slNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774512530; x=1775117330; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=PUqdYCoBg/kEy42eZkJV8irdcP7MA2fDPdgYAg1G1X4=; b=fOxi/ba8dwQalV+Eqd8J1A8BopqxI4m8xVW+CjWIkug6OgGC+pGz0sU69TAw8xDkyA VwSRE5BeRPch7P+gT8jOXjWJ5GzbSBZ+zrFOyYRcv0cuCiIq/5n91x2Ddnlrk6HcH8Er pOd2f9W4HgIl0Pn268MaImI5z1gphosM/LZRqfUp0fjb7pgmLSkcZaUBqFMs/hRQNyfr HYpy/pLXunwyftXCwnC9xRQRjsP60d4RK9Yj+ahA2W8xyTMG2HA7gDOYHSusZSQjuy4a ig19c9Kv/QfHQ2bXMssQBT/HOo9uLCNU3avGgVzjA2q5jrSc9pTuz1DdmS08SUWb/J9p iSSQ== X-Forwarded-Encrypted: i=1; AJvYcCWsf17gqbEFS5aIUkiVNSggTEdRP8zSX4Et+uMH+1JOMFAYcoXfUHhK26B1aXhrSzTrtPSLLH6+Rw==@kvack.org X-Gm-Message-State: AOJu0YzVHmn1ii8CtuVx/fZtBXojFgM1ahcOL6EjA31pB60DWiP0ldE2 2PmLmYQd/uD/b8sZyqH711f7DcKy6J9RTtXiBRouOqNs/Qn412VLSsB+coc1xirlB8W3fNt5D++ FyUvqAw== X-Received: from dlx24.prod.google.com ([2002:a05:7022:98:b0:12a:6ccc:6d06]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:4387:b0:128:d107:da0f with SMTP id a92af1059eb24-12a96e5405cmr4138769c88.10.1774512529879; Thu, 26 Mar 2026 01:08:49 -0700 (PDT) Date: Thu, 26 Mar 2026 01:08:34 -0700 In-Reply-To: <20260326080836.695207-1-surenb@google.com> Mime-Version: 1.0 References: <20260326080836.695207-1-surenb@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: <20260326080836.695207-5-surenb@google.com> Subject: [PATCH v5 4/6] mm/vma: use vma_start_write_killable() in vma operations From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, david@kernel.org, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, lorenzo.stoakes@oracle.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@suse.cz, jannh@google.com, rppt@kernel.org, mhocko@suse.com, pfalcato@suse.de, kees@kernel.org, maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au, chleroy@kernel.org, borntraeger@linux.ibm.com, frankja@linux.ibm.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com, gerald.schaefer@linux.ibm.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 47A7040002 X-Stat-Signature: bq56os5t3ksghjusmqa5abqaae9qg7tc X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1774512531-483052 X-HE-Meta: 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 4bHzZeJv 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Replace vma_start_write() with vma_start_write_killable(), improving reaction time to the kill signal. Replace vma_start_write() calls when we operate on VMAs. In a number of places we now lock VMA earlier than before to avoid doing work and undoing it later if a fatal signal is pending. This is safe because the moves are happening within sections where we already hold the mmap_write_lock, so the moves do not change the locking order relative to other kernel locks. Suggested-by: Matthew Wilcox Signed-off-by: Suren Baghdasaryan --- mm/vma.c | 130 +++++++++++++++++++++++++++++++++++++------------- mm/vma_exec.c | 6 ++- 2 files changed, 101 insertions(+), 35 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index ba78ab1f397a..7ee68fbfea03 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -524,6 +524,17 @@ __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT); } + /* + * Lock VMAs before cloning to avoid extra work if fatal signal + * is pending. + */ + err = vma_start_write_killable(vma); + if (err) + goto out_free_vma; + err = vma_start_write_killable(new); + if (err) + goto out_free_vma; + err = -ENOMEM; vma_iter_config(vmi, new->vm_start, new->vm_end); if (vma_iter_prealloc(vmi, new)) @@ -543,9 +554,6 @@ __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); - vma_start_write(vma); - vma_start_write(new); - init_vma_prep(&vp, vma); vp.insert = new; vma_prepare(&vp); @@ -900,12 +908,22 @@ static __must_check struct vm_area_struct *vma_merge_existing_range( } /* No matter what happens, we will be adjusting middle. */ - vma_start_write(middle); + err = vma_start_write_killable(middle); + if (err) { + /* Ensure error propagates. */ + vmg->give_up_on_oom = false; + goto abort; + } if (merge_right) { vma_flags_t next_sticky; - vma_start_write(next); + err = vma_start_write_killable(next); + if (err) { + /* Ensure error propagates. */ + vmg->give_up_on_oom = false; + goto abort; + } vmg->target = next; next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS); vma_flags_set_mask(&sticky_flags, next_sticky); @@ -914,7 +932,12 @@ static __must_check struct vm_area_struct *vma_merge_existing_range( if (merge_left) { vma_flags_t prev_sticky; - vma_start_write(prev); + err = vma_start_write_killable(prev); + if (err) { + /* Ensure error propagates. */ + vmg->give_up_on_oom = false; + goto abort; + } vmg->target = prev; prev_sticky = vma_flags_and_mask(&prev->flags, VMA_STICKY_FLAGS); @@ -1170,10 +1193,12 @@ int vma_expand(struct vma_merge_struct *vmg) vma_flags_t sticky_flags = vma_flags_and_mask(&vmg->vma_flags, VMA_STICKY_FLAGS); vma_flags_t target_sticky; - int err = 0; + int err; mmap_assert_write_locked(vmg->mm); - vma_start_write(target); + err = vma_start_write_killable(target); + if (err) + return err; target_sticky = vma_flags_and_mask(&target->flags, VMA_STICKY_FLAGS); @@ -1201,6 +1226,13 @@ int vma_expand(struct vma_merge_struct *vmg) * we don't need to account for vmg->give_up_on_mm here. */ if (remove_next) { + /* + * Lock the VMA early to avoid extra work if fatal signal + * is pending. + */ + err = vma_start_write_killable(next); + if (err) + return err; err = dup_anon_vma(target, next, &anon_dup); if (err) return err; @@ -1214,7 +1246,6 @@ int vma_expand(struct vma_merge_struct *vmg) if (remove_next) { vma_flags_t next_sticky; - vma_start_write(next); vmg->__remove_next = true; next_sticky = vma_flags_and_mask(&next->flags, VMA_STICKY_FLAGS); @@ -1252,9 +1283,14 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgoff_t pgoff) { struct vma_prepare vp; + int err; WARN_ON((vma->vm_start != start) && (vma->vm_end != end)); + err = vma_start_write_killable(vma); + if (err) + return err; + if (vma->vm_start < start) vma_iter_config(vmi, vma->vm_start, start); else @@ -1263,8 +1299,6 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, if (vma_iter_prealloc(vmi, NULL)) return -ENOMEM; - vma_start_write(vma); - init_vma_prep(&vp, vma); vma_prepare(&vp); vma_adjust_trans_huge(vma, start, end, NULL); @@ -1453,7 +1487,9 @@ static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, if (error) goto end_split_failed; } - vma_start_write(next); + error = vma_start_write_killable(next); + if (error) + goto munmap_gather_failed; mas_set(mas_detach, vms->vma_count++); error = mas_store_gfp(mas_detach, next, GFP_KERNEL); if (error) @@ -1848,12 +1884,16 @@ static void vma_link_file(struct vm_area_struct *vma, bool hold_rmap_lock) static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma) { VMA_ITERATOR(vmi, mm, 0); + int err; + + err = vma_start_write_killable(vma); + if (err) + return err; vma_iter_config(&vmi, vma->vm_start, vma->vm_end); if (vma_iter_prealloc(&vmi, vma)) return -ENOMEM; - vma_start_write(vma); vma_iter_store_new(&vmi, vma); vma_link_file(vma, /* hold_rmap_lock= */false); mm->map_count++; @@ -2239,9 +2279,8 @@ int mm_take_all_locks(struct mm_struct *mm) * is reached. */ for_each_vma(vmi, vma) { - if (signal_pending(current)) + if (signal_pending(current) || vma_start_write_killable(vma)) goto out_unlock; - vma_start_write(vma); } vma_iter_init(&vmi, mm, 0); @@ -2540,8 +2579,8 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, struct mmap_action *action) { struct vma_iterator *vmi = map->vmi; - int error = 0; struct vm_area_struct *vma; + int error; /* * Determine the object being mapped and call the appropriate @@ -2552,6 +2591,14 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, if (!vma) return -ENOMEM; + /* + * Lock the VMA early to avoid extra work if fatal signal + * is pending. + */ + error = vma_start_write_killable(vma); + if (error) + goto free_vma; + vma_iter_config(vmi, map->addr, map->end); vma_set_range(vma, map->addr, map->end, map->pgoff); vma->flags = map->vma_flags; @@ -2582,8 +2629,6 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, WARN_ON_ONCE(!arch_validate_flags(map->vm_flags)); #endif - /* Lock the VMA since it is modified after insertion into VMA tree */ - vma_start_write(vma); vma_iter_store_new(vmi, vma); map->mm->map_count++; vma_link_file(vma, action->hide_from_rmap_until_complete); @@ -2878,6 +2923,7 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, unsigned long addr, unsigned long len, vma_flags_t vma_flags) { struct mm_struct *mm = current->mm; + int err; /* * Check against address space limits by the changed size @@ -2910,24 +2956,33 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, if (vma_merge_new_range(&vmg)) goto out; - else if (vmg_nomem(&vmg)) + if (vmg_nomem(&vmg)) { + err = -ENOMEM; goto unacct_fail; + } } if (vma) vma_iter_next_range(vmi); /* create a vma struct for an anonymous mapping */ vma = vm_area_alloc(mm); - if (!vma) + if (!vma) { + err = -ENOMEM; goto unacct_fail; + } vma_set_anonymous(vma); vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT); vma->flags = vma_flags; vma->vm_page_prot = vm_get_page_prot(vma_flags_to_legacy(vma_flags)); - vma_start_write(vma); - if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) + if (vma_start_write_killable(vma)) { + err = -EINTR; + goto vma_lock_fail; + } + if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) { + err = -ENOMEM; goto mas_store_fail; + } mm->map_count++; validate_mm(mm); @@ -2942,10 +2997,11 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, return 0; mas_store_fail: +vma_lock_fail: vm_area_free(vma); unacct_fail: vm_unacct_memory(len >> PAGE_SHIFT); - return -ENOMEM; + return err; } /** @@ -3112,8 +3168,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *next; unsigned long gap_addr; - int error = 0; VMA_ITERATOR(vmi, mm, vma->vm_start); + int error; if (!vma_test(vma, VMA_GROWSUP_BIT)) return -EFAULT; @@ -3149,12 +3205,14 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) { - vma_iter_free(&vmi); - return -ENOMEM; + error = -ENOMEM; + goto vma_prep_fail; } /* Lock the VMA before expanding to prevent concurrent page faults */ - vma_start_write(vma); + error = vma_start_write_killable(vma); + if (error) + goto vma_lock_fail; /* We update the anon VMA tree. */ anon_vma_lock_write(vma->anon_vma); @@ -3183,8 +3241,10 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) } } anon_vma_unlock_write(vma->anon_vma); - vma_iter_free(&vmi); validate_mm(mm); +vma_lock_fail: +vma_prep_fail: + vma_iter_free(&vmi); return error; } #endif /* CONFIG_STACK_GROWSUP */ @@ -3197,8 +3257,8 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *prev; - int error = 0; VMA_ITERATOR(vmi, mm, vma->vm_start); + int error; if (!vma_test(vma, VMA_GROWSDOWN_BIT)) return -EFAULT; @@ -3228,12 +3288,14 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) { - vma_iter_free(&vmi); - return -ENOMEM; + error = -ENOMEM; + goto vma_prep_fail; } /* Lock the VMA before expanding to prevent concurrent page faults */ - vma_start_write(vma); + error = vma_start_write_killable(vma); + if (error) + goto vma_lock_fail; /* We update the anon VMA tree. */ anon_vma_lock_write(vma->anon_vma); @@ -3263,8 +3325,10 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) } } anon_vma_unlock_write(vma->anon_vma); - vma_iter_free(&vmi); validate_mm(mm); +vma_lock_fail: +vma_prep_fail: + vma_iter_free(&vmi); return error; } diff --git a/mm/vma_exec.c b/mm/vma_exec.c index 5cee8b7efa0f..8ddcc791d828 100644 --- a/mm/vma_exec.c +++ b/mm/vma_exec.c @@ -41,6 +41,7 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift) struct vm_area_struct *next; struct mmu_gather tlb; PAGETABLE_MOVE(pmc, vma, vma, old_start, new_start, length); + int err; BUG_ON(new_start > new_end); @@ -56,8 +57,9 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift) * cover the whole range: [new_start, old_end) */ vmg.target = vma; - if (vma_expand(&vmg)) - return -ENOMEM; + err = vma_expand(&vmg); + if (err) + return err; /* * move the page tables downwards, on failure we rely on -- 2.53.0.1018.g2bb0e51243-goog