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 ABEB0C71153 for ; Sat, 2 Sep 2023 22:38:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235066AbjIBWif (ORCPT ); Sat, 2 Sep 2023 18:38:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229968AbjIBWif (ORCPT ); Sat, 2 Sep 2023 18:38:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24E2B1A7 for ; Sat, 2 Sep 2023 15:38:32 -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 B814A60EE9 for ; Sat, 2 Sep 2023 22:38:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1BA25C433C8; Sat, 2 Sep 2023 22:38:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1693694311; bh=ghawwxtUOiUCBLv4uJBUAmXkhj31MXMgSs2uN85tnpI=; h=Date:To:From:Subject:From; b=P1htQ7s1EemrKPsd5F4Fe1A6TtXt8PjhevQrMq5zR9HB4I8/DyJi4oe9aius8/myI 0eOZ0fAAXqzmhW7V74wFIraHtIJjsWjFgDzdoLPABgfxADupIPcUrXChh/7ugKGMfN ujUqrpetlV5tdPBKdl8n64h3G4BIKZAJK3fhCVCM= Date: Sat, 02 Sep 2023 15:38:30 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, mgorman@techsingularity.net, david@redhat.com, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode.patch added to mm-unstable branch Message-Id: <20230902223831.1BA25C433C8@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/compaction: correctly return failure with bogus compound_order in strict mode has been added to the -mm mm-unstable branch. Its filename is mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Kemeng Shi Subject: mm/compaction: correctly return failure with bogus compound_order in strict mode Date: Fri, 1 Sep 2023 23:51:38 +0800 In strict mode, we should return 0 if there is any hole in pageblock. If we successfully isolated pages at beginning at pageblock and then have a bogus compound_order outside pageblock in next page. We will abort search loop with blockpfn > end_pfn. Although we will limit blockpfn to end_pfn, we will treat it as a successful isolation in strict mode as blockpfn is not < end_pfn and return partial isolated pages. Then isolate_freepages_range may success unexpectly with hole in isolated range. Link: https://lkml.kernel.org/r/20230901155141.249860-4-shikemeng@huaweicloud.com Fixes: 9fcd6d2e052e ("mm, compaction: skip compound pages by order in free scanner") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang Acked-by: Mel Gorman Cc: David Hildenbrand Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/compaction.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/compaction.c~mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode +++ a/mm/compaction.c @@ -626,11 +626,12 @@ static unsigned long isolate_freepages_b if (PageCompound(page)) { const unsigned int order = compound_order(page); - if (likely(order <= MAX_ORDER)) { + if (blockpfn + (1UL << order) <= end_pfn) { blockpfn += (1UL << order) - 1; page += (1UL << order) - 1; nr_scanned += (1UL << order) - 1; } + goto isolate_fail; } @@ -678,8 +679,7 @@ isolate_fail: spin_unlock_irqrestore(&cc->zone->lock, flags); /* - * There is a tiny chance that we have read bogus compound_order(), - * so be careful to not go outside of the pageblock. + * Be careful to not go outside of the pageblock. */ if (unlikely(blockpfn > end_pfn)) blockpfn = end_pfn; _ Patches currently in -mm which might be from shikemeng@huaweicloud.com are mm-compaction-use-correct-list-in-move_freelist_head-tail.patch mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.patch mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode.patch mm-compaction-remove-repeat-compact_blockskip_flush-check-in-reset_isolation_suitable.patch mm-compaction-improve-comment-of-is_via_compact_memory.patch mm-compaction-factor-out-code-to-test-if-we-should-run-compaction-for-target-order.patch