From patchwork Tue May 24 02:53:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiaqi Yan X-Patchwork-Id: 12859633 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 BCB2FC433FE for ; Tue, 24 May 2022 02:54:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 56B1D8D0001; Mon, 23 May 2022 22:54:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F8A36B007B; Mon, 23 May 2022 22:54:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 395F28D0001; Mon, 23 May 2022 22:54:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 23D256B0078 for ; Mon, 23 May 2022 22:54:05 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 07E9F356A9 for ; Tue, 24 May 2022 02:54:05 +0000 (UTC) X-FDA: 79499117250.10.72B58D9 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) by imf25.hostedemail.com (Postfix) with ESMTP id C7F66A0028 for ; Tue, 24 May 2022 02:53:36 +0000 (UTC) Received: by mail-pj1-f73.google.com with SMTP id 14-20020a17090a08ce00b001dfd1149f51so7721280pjn.9 for ; Mon, 23 May 2022 19:54:04 -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=ui1g2HLuECtWsWc0uR9htrijQ1M7r9FKoGS77rnumqs=; b=d0eT+qcBem0qBRc26jTQ2bKrWi0Q2PIOEKUbEIIz4cYH0E/zi2wxAkJZ1ltgidnoSo avxlgmNKoj16BKkz+0Sv6zPghYbyi/Uw0HBpvEA26IpWE9UQn95jA4DMOEYkr8Ak5sAh OCKnjrkUL3TqaIbbek/R0bySEOsQOcHG9hzBm2HNn8rKK4eFWgXWxfyWJxOtyZ8QeNcH KpcT3WtpByPNHm8re5augNeuFIP5vuXFYvSI3XcCVpRiLTZYGtDHwIn+iPse3eJN2BSO QDaYdD4ohr8gQXutURlIFLJ3CwWymCd5oC/Ki4R4JOBgnTvsKrKHsbNuHH/5zBfTnw9C Nefg== 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=ui1g2HLuECtWsWc0uR9htrijQ1M7r9FKoGS77rnumqs=; b=3xTT6QZZYGKRluJSp42Qd4ToycOg6r86001LQfMbOqzaE2LcYA91CU9yfgPkYx4JMS cTapGWuAIzG8XadMNHwbDEKBoad7zBfYqMmlz+ZTuGmztkA6bMmSTOVFShuZAfSIEltV jNcPssLMFF0dTXIOnhI5uY8/ur8UihFuJPoafNfp8r8NCJGTYAQB55fDF8gPo9wp8Kms AhRDO8Ud22Nb14TSac4VqPrg1/tYdbji92E6WnXpchwJHDx4Dx7z4EWlanYzmfyWsSeE rSqkhA8QksigwjtYx+AR7Dd0X0oFCmIoS4P1uDlgv6mkzfP2I1Sglt0LHLwb9hQibwr4 rbEw== X-Gm-Message-State: AOAM532ZpDhKTb88mic98cp3fPYB1Efyen4wZKJilvkJtoyFpfNi+pLO oU0cGxpyk/xJg4IQzh80b75UXEd4TWLdqA== X-Google-Smtp-Source: ABdhPJzGYYdLyCTsqOF+9Z8DZRqTHUNVs4AkXNeX4W7vQkZuS9OlRRBDeuLOkjfvuPnJg+tQQVDKEJm3ZhajgA== X-Received: from yjqkernel.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1837]) (user=jiaqiyan job=sendgmr) by 2002:a17:902:b289:b0:161:df12:8b04 with SMTP id u9-20020a170902b28900b00161df128b04mr23822534plr.125.1653360843422; Mon, 23 May 2022 19:54:03 -0700 (PDT) Date: Mon, 23 May 2022 19:53:52 -0700 In-Reply-To: <20220524025352.1381911-1-jiaqiyan@google.com> Message-Id: <20220524025352.1381911-3-jiaqiyan@google.com> Mime-Version: 1.0 References: <20220524025352.1381911-1-jiaqiyan@google.com> X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog Subject: [PATCH v3 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: rspam11 X-Rspamd-Queue-Id: C7F66A0028 X-Stat-Signature: carskfz8cpqpdybds68k4b9ipifccyxt X-Rspam-User: Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=d0eT+qcB; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf25.hostedemail.com: domain of 3y0iMYggKCKgRQIYQgIVOWWOTM.KWUTQVcf-UUSdIKS.WZO@flex--jiaqiyan.bounces.google.com designates 209.85.216.73 as permitted sender) smtp.mailfrom=3y0iMYggKCKgRQIYQgIVOWWOTM.KWUTQVcf-UUSdIKS.WZO@flex--jiaqiyan.bounces.google.com X-HE-Tag: 1653360816-146244 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 | 77 ++++++++++++++++++++++++++++++------------------- 1 file changed, 48 insertions(+), 29 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 1b08e31ba081a..98976622ee7c5 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1716,7 +1716,7 @@ 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); @@ -1772,7 +1772,7 @@ 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) { @@ -1944,10 +1944,7 @@ 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 @@ -1958,40 +1955,44 @@ 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); @@ -1999,12 +2000,23 @@ 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); @@ -2020,9 +2032,9 @@ static void collapse_file(struct mm_struct *mm, khugepaged_pages_collapsed++; } else { - struct page *page; - - /* Something went wrong: roll back page cache changes */ + /* + * Something went wrong: roll back page cache changes + */ xas_lock_irq(&xas); mapping->nrpages -= nr_none; @@ -2055,6 +2067,13 @@ 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;