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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A88A5EB64DA for ; Mon, 19 Jun 2023 20:20:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230029AbjFSUUV (ORCPT ); Mon, 19 Jun 2023 16:20:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229808AbjFSUUM (ORCPT ); Mon, 19 Jun 2023 16:20:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6A6ED3 for ; Mon, 19 Jun 2023 13:20:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 49C3060EB0 for ; Mon, 19 Jun 2023 20:20:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B9EAC433C0; Mon, 19 Jun 2023 20:20:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1687206009; bh=4/5rPh+FFRptgEV2fH1b4h10dJZCkO6IxixKY3d7RUQ=; h=Date:To:From:Subject:From; b=xG5FjmcVYIHuVZ0vPGXxewPrB4KrOdJsfa85PRW7TjVR7bdFQ9RQySBjJU0FHozn/ qr2oIT5cvuKce77QSlDWwa+NERQwjYWJaQLHksnokqY9AgjYFEzOcb8WDMbnfRlyH8 3N4P00HdfwdbZr3FOsw78oSwLmZ3iDAjS20Pcf+c= Date: Mon, 19 Jun 2023 13:20:09 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, shy828301@gmail.com, peterx@redhat.com, mike.kravetz@oracle.com, kirill@shutemov.name, jiaqiyan@google.com, hughd@google.com, david@redhat.com, stevensd@chromium.org, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-khugepaged-fix-iteration-in-collapse_file.patch removed from -mm tree Message-Id: <20230619202009.9B9EAC433C0@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/khugepaged: fix iteration in collapse_file has been removed from the -mm tree. Its filename was mm-khugepaged-fix-iteration-in-collapse_file.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Stevens Subject: mm/khugepaged: fix iteration in collapse_file Date: Wed, 7 Jun 2023 14:31:35 +0900 Remove an unnecessary call to xas_set(index) when iterating over the target range in collapse_file. The extra call to xas_set reset the xas cursor to the top of the tree, causing the xas_next call on the next iteration to walk the tree to index instead of advancing to index+1. This returned the same page again, which would cause collapse_file to fail because the page is already locked. This bug was hidden when CONFIG_DEBUG_VM was set. When that config was used, the xas_load in a subsequent VM_BUG_ON assert would walk xas from the top of the tree to index, causing the xas_next call on the next loop iteration to advance the cursor as expected. Link: https://lkml.kernel.org/r/20230607053135.2087354-1-stevensd@google.com Fixes: a2e17cc2efc7 ("mm/khugepaged: maintain page cache uptodate flag") Signed-off-by: David Stevens Reviewed-by: Peter Xu Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jiaqi Yan Cc: Kirill A . Shutemov Cc: Matthew Wilcox Cc: Yang Shi Cc: Mike Kravetz Signed-off-by: Andrew Morton --- mm/khugepaged.c | 1 - 1 file changed, 1 deletion(-) --- a/mm/khugepaged.c~mm-khugepaged-fix-iteration-in-collapse_file +++ a/mm/khugepaged.c @@ -2070,7 +2070,6 @@ static int collapse_file(struct mm_struc TTU_IGNORE_MLOCK | TTU_BATCH_FLUSH); xas_lock_irq(&xas); - xas_set(&xas, index); VM_BUG_ON_PAGE(page != xas_load(&xas), page); _ Patches currently in -mm which might be from stevensd@chromium.org are mm-shmem-fix-race-in-shmem_undo_range-w-thp.patch