From patchwork Fri May 27 19:07:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiaqi Yan X-Patchwork-Id: 12863718 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]) by smtp.lore.kernel.org (Postfix) with ESMTP id AAAC9C433F5 for ; Fri, 27 May 2022 19:07:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 297388D0006; Fri, 27 May 2022 15:07:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 246698D0001; Fri, 27 May 2022 15:07:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B9E18D0006; Fri, 27 May 2022 15:07:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id F2B178D0001 for ; Fri, 27 May 2022 15:07:41 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id C9DF23434E for ; Fri, 27 May 2022 19:07:41 +0000 (UTC) X-FDA: 79512457122.08.8D4EF69 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) by imf19.hostedemail.com (Postfix) with ESMTP id CD5BD1A0042 for ; Fri, 27 May 2022 19:07:27 +0000 (UTC) Received: by mail-pj1-f73.google.com with SMTP id m5-20020a17090a4d8500b001e0cfe135c7so3161377pjh.3 for ; Fri, 27 May 2022 12:07:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=IVBTRgxgXztIbEBUVVIKTt5XxYZaro1ZXA6mGjPQPio=; b=pqk6Yfp710zgwJFmweIzqOZaWJfsVHO034gLfb6yG8yy9RvU0UwRZReRHRmteFaj9c Bd0tDrokZDL7yd5HP/AppzTiOm4l1Vb00IeRA3WRoHuxINOaLscP/WheDaUEGaSp1uwP vJ5PeLH2KmGuqmwLGsI1WcrFwtdVG65ngvAQNU2ZCzUUIdSEk9dDccQaF5G8ZXfS7Bs2 effkDMCeK/mqNa9QAa9+myK8UFRiarFTJ5ppo/DYjYza7qgrCFfw2DBC9HgOsoaRwees OgeWbadUIjjLbGa9yWh95Wu0/jflX2atIXxWrfepxkzgbMrpXUrDyqWGslBFAgpUvTzs eYtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=IVBTRgxgXztIbEBUVVIKTt5XxYZaro1ZXA6mGjPQPio=; b=Gm2ncf4VVwVEkn2JrIKTRQNFjqh6L8VhaQ9yOBTOs5LVRp03LRZyy4AMrnwtZiqW4Q FAhNirHpoRryJgqyK1TQ4iXUoZ/DDbuiVnAMN3Rdo0x/rGLk5nM8Kb7HY5yJlpU+k/F3 4ikNz+kLfbIWg/2D6KDzGAgG7GHW3TDdeR65gSYgBWnySwob9snS1JGwekP+82v206Bu OcgaP2HRjyN69CMwdS+V6Qf/TfXIXcCEm/f3C2NNiwMXEw83Cns/qRAHaBrCSkFfqRru PO7OGy92Np0bdWH7zQdJcsW2lFCxOtQCdUc2cY8PWYHysO7Ruceu8mVHJrME3MGv5Ban Io6g== X-Gm-Message-State: AOAM533ElKYzga85nifc/qfFEMqo4blYtc1h3VAGwpZNhsoYtMkBraVk DLo8Q2QgRYvwEPRWUr+rQI6PPpSByGpu4Q== X-Google-Smtp-Source: ABdhPJzTDYrS4s1L8xhvQEM+uXrGHRmPelzzBBxM4XIKz+1CPJ+TtaPTFIt7TVZQl/QiHMNCcdWnKQFYffHaJg== X-Received: from yjqkernel.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1837]) (user=jiaqiyan job=sendgmr) by 2002:a05:6a00:1a91:b0:518:7bca:d095 with SMTP id e17-20020a056a001a9100b005187bcad095mr34954401pfv.13.1653678460373; Fri, 27 May 2022 12:07:40 -0700 (PDT) Date: Fri, 27 May 2022 12:07:31 -0700 In-Reply-To: <20220527190731.322722-1-jiaqiyan@google.com> Message-Id: <20220527190731.322722-3-jiaqiyan@google.com> Mime-Version: 1.0 References: <20220527190731.322722-1-jiaqiyan@google.com> X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog Subject: [PATCH v4 2/2] mm: khugepaged: recover from poisoned file-backed memory From: Jiaqi Yan To: shy828301@gmail.com, tongtiangen@huawei.com Cc: tony.luck@intel.com, naoya.horiguchi@nec.com, kirill.shutemov@linux.intel.com, linmiaohe@huawei.com, juew@google.com, jiaqiyan@google.com, linux-mm@kvack.org X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: CD5BD1A0042 X-Rspam-User: X-Stat-Signature: 4dh3kxnzbwn7fna6rng1rb7b36qsxitg Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=pqk6Yfp7; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf19.hostedemail.com: domain of 3fCGRYggKCB8ED5LDT5IBJJBG9.7JHGDIPS-HHFQ57F.JMB@flex--jiaqiyan.bounces.google.com designates 209.85.216.73 as permitted sender) smtp.mailfrom=3fCGRYggKCB8ED5LDT5IBJJBG9.7JHGDIPS-HHFQ57F.JMB@flex--jiaqiyan.bounces.google.com X-HE-Tag: 1653678447-292330 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Make collapse_file roll back when copying pages failed. More concretely: * extract copying operations into a separate loop * postpone the updates for nr_none until both scanning and copying succeeded * postpone joining small xarray entries until both scanning and copying succeeded * postpone the update operations to NR_XXX_THPS * for non-SHMEM file, roll back filemap_nr_thps_inc if scan succeeded but copying failed Signed-off-by: Jiaqi Yan Reviewed-by: Yang Shi --- mm/khugepaged.c | 73 ++++++++++++++++++++++++++++++------------------- 1 file changed, 45 insertions(+), 28 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0dd28ecc915d1..1ea485c315756 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1706,7 +1706,7 @@ static void collapse_file(struct mm_struct *mm, { struct address_space *mapping = file->f_mapping; gfp_t gfp; - struct page *new_page; + struct page *new_page, *page, *tmp; pgoff_t index, end = start + HPAGE_PMD_NR; LIST_HEAD(pagelist); XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); @@ -1762,7 +1762,7 @@ static void collapse_file(struct mm_struct *mm, xas_set(&xas, start); for (index = start; index < end; index++) { - struct page *page = xas_next(&xas); + page = xas_next(&xas); VM_BUG_ON(index != xas.xa_index); if (is_shmem) { @@ -1934,10 +1934,7 @@ static void collapse_file(struct mm_struct *mm, } nr = thp_nr_pages(new_page); - if (is_shmem) - __mod_lruvec_page_state(new_page, NR_SHMEM_THPS, nr); - else { - __mod_lruvec_page_state(new_page, NR_FILE_THPS, nr); + if (!is_shmem) { filemap_nr_thps_inc(mapping); /* * Paired with smp_mb() in do_dentry_open() to ensure @@ -1948,40 +1945,44 @@ static void collapse_file(struct mm_struct *mm, smp_mb(); if (inode_is_open_for_write(mapping->host)) { result = SCAN_FAIL; - __mod_lruvec_page_state(new_page, NR_FILE_THPS, -nr); filemap_nr_thps_dec(mapping); goto xa_locked; } } - if (nr_none) { - __mod_lruvec_page_state(new_page, NR_FILE_PAGES, nr_none); - if (is_shmem) - __mod_lruvec_page_state(new_page, NR_SHMEM, nr_none); - } - - /* Join all the small entries into a single multi-index entry */ - xas_set_order(&xas, start, HPAGE_PMD_ORDER); - xas_store(&xas, new_page); xa_locked: xas_unlock_irq(&xas); xa_unlocked: if (result == SCAN_SUCCEED) { - struct page *page, *tmp; - /* * Replacing old pages with new one has succeeded, now we - * need to copy the content and free the old pages. + * attempt to copy the contents. */ index = start; - list_for_each_entry_safe(page, tmp, &pagelist, lru) { + list_for_each_entry(page, &pagelist, lru) { while (index < page->index) { clear_highpage(new_page + (index % HPAGE_PMD_NR)); index++; } - copy_highpage(new_page + (page->index % HPAGE_PMD_NR), - page); + if (copy_highpage_mc(new_page + (page->index % HPAGE_PMD_NR), page)) { + result = SCAN_COPY_MC; + break; + } + index++; + } + while (result == SCAN_SUCCEED && index < end) { + clear_highpage(new_page + (page->index % HPAGE_PMD_NR)); + index++; + } + } + + if (result == SCAN_SUCCEED) { + /* + * Copying old pages to huge one has succeeded, now we + * need to free the old pages. + */ + list_for_each_entry_safe(page, tmp, &pagelist, lru) { list_del(&page->lru); page->mapping = NULL; page_ref_unfreeze(page, 1); @@ -1989,12 +1990,23 @@ static void collapse_file(struct mm_struct *mm, ClearPageUnevictable(page); unlock_page(page); put_page(page); - index++; } - while (index < end) { - clear_highpage(new_page + (index % HPAGE_PMD_NR)); - index++; + + xas_lock_irq(&xas); + if (is_shmem) + __mod_lruvec_page_state(new_page, NR_SHMEM_THPS, nr); + else + __mod_lruvec_page_state(new_page, NR_FILE_THPS, nr); + + if (nr_none) { + __mod_lruvec_page_state(new_page, NR_FILE_PAGES, nr_none); + if (is_shmem) + __mod_lruvec_page_state(new_page, NR_SHMEM, nr_none); } + /* Join all the small entries into a single multi-index entry. */ + xas_set_order(&xas, start, HPAGE_PMD_ORDER); + xas_store(&xas, new_page); + xas_unlock_irq(&xas); SetPageUptodate(new_page); page_ref_add(new_page, HPAGE_PMD_NR - 1); @@ -2010,8 +2022,6 @@ static void collapse_file(struct mm_struct *mm, khugepaged_pages_collapsed++; } else { - struct page *page; - /* Something went wrong: roll back page cache changes */ xas_lock_irq(&xas); mapping->nrpages -= nr_none; @@ -2045,6 +2055,13 @@ static void collapse_file(struct mm_struct *mm, xas_lock_irq(&xas); } VM_BUG_ON(nr_none); + /* + * Undo the updates of filemap_nr_thps_inc for non-SHMEM file only. + * This undo is not needed unless failure is due to SCAN_COPY_MC. + */ + if (!is_shmem && result == SCAN_COPY_MC) + filemap_nr_thps_dec(mapping); + xas_unlock_irq(&xas); new_page->mapping = NULL;