From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85F4D8BEA; Mon, 21 Apr 2025 19:49:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745264951; cv=none; b=ciRnQJJO91k6jBcpczkzU2ZyfHIO9p+6vfR9FtGT55JBaojMdJEl+yrmAYD8MdQgZkKj73y0lR/UJwQZROTF0tCKJGh6BtioTHe+qYmuqNqwceLhy6Hrxb9iARETwpLcktOAs92ImwyHQ0OBpotfMmKolggaiOre9XoWVOA/B/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745264951; c=relaxed/simple; bh=ZKwgzBMd2ynxOHDU8094XcyKSAz/RG1KL1e2R/kBuqk=; h=Date:To:From:Subject:Message-Id; b=NC5ZQ1uiCnzD3d1VsGFBTg1oaMbmWv7prcUUZL+q6owSME0Ti0rapn340X5hBePzx0ZQzkMD+oAiqVUU3MFLtfgFZOLkoZbKjcLlkbrZ5TPinX43BtJsSqTN/y5i26LaXecvgO1aHvj78klM6R09g+P4g7GBoPsKa3XI+8nZO1E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=m1E68Gh7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="m1E68Gh7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFD74C4CEE4; Mon, 21 Apr 2025 19:49:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1745264951; bh=ZKwgzBMd2ynxOHDU8094XcyKSAz/RG1KL1e2R/kBuqk=; h=Date:To:From:Subject:From; b=m1E68Gh7HotD1gV7wsFVRCbaETYjMEZFdgc2Pf95rFqqXNtQXVUi5u0GCxzkZUaEg SPQiLu2r3VbnP9eEBtgaH4i6byyL4ljMR+mhjkHhQw+vkAedNH3+nzWDdDkhgZ9wTn 0mwKf5dS+trORHKkyw7CthJ9/pmUZ4iH1WwfeXP0= Date: Mon, 21 Apr 2025 12:49:10 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,yuzhao@google.com,wangkefeng.wang@huawei.com,stable@vger.kernel.org,david@redhat.com,tujinjiang@huawei.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch added to mm-hotfixes-unstable branch Message-Id: <20250421194910.DFD74C4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/contig_alloc: fix alloc_contig_range when __GFP_COMP and order < MAX_ORDER has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch This patch will later appear in the mm-hotfixes-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: Jinjiang Tu Subject: mm/contig_alloc: fix alloc_contig_range when __GFP_COMP and order < MAX_ORDER Date: Mon, 21 Apr 2025 09:36:20 +0800 When calling alloc_contig_range() with __GFP_COMP and the order of requested pfn range is pageblock_order, less than MAX_ORDER, I triggered WARNING as follows: PFN range: requested [2150105088, 2150105600), allocated [2150105088, 2150106112) WARNING: CPU: 3 PID: 580 at mm/page_alloc.c:6877 alloc_contig_range+0x280/0x340 alloc_contig_range() marks pageblocks of the requested pfn range to be isolated, migrate these pages if they are in use and will be freed to MIGRATE_ISOLATED freelist. Suppose two alloc_contig_range() calls at the same time and the requested pfn range are [0x80280000, 0x80280200) and [0x80280200, 0x80280400) respectively. Suppose the two memory range are in use, then alloc_contig_range() will migrate and free these pages to MIGRATE_ISOLATED freelist. __free_one_page() will merge MIGRATE_ISOLATE buddy to larger buddy, resulting in a MAX_ORDER buddy. Finally, find_large_buddy() in alloc_contig_range() returns a MAX_ORDER buddy and results in WARNING. To fix it, call free_contig_range() to free the excess pfn range. Link: https://lkml.kernel.org/r/20250421013620.459740-1-tujinjiang@huawei.com Fixes: e98337d11bbd ("mm/contig_alloc: support __GFP_COMP") Signed-off-by: Jinjiang Tu Reviewed-by: Zi Yan Cc: David Hildenbrand Cc: Kefeng Wang Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton --- mm/page_alloc.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/mm/page_alloc.c~mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order +++ a/mm/page_alloc.c @@ -6706,6 +6706,7 @@ int alloc_contig_range_noprof(unsigned l .alloc_contig = true, }; INIT_LIST_HEAD(&cc.migratepages); + bool is_range_aligned; gfp_mask = current_gfp_context(gfp_mask); if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask)) @@ -6794,7 +6795,14 @@ int alloc_contig_range_noprof(unsigned l goto done; } - if (!(gfp_mask & __GFP_COMP)) { + /* + * With __GFP_COMP and the requested order < MAX_PAGE_ORDER, + * isolated free pages can have higher order than the requested + * one. Use split_free_pages() to free out of range pages. + */ + is_range_aligned = is_power_of_2(end - start); + if (!(gfp_mask & __GFP_COMP) || + (is_range_aligned && ilog2(end - start) < MAX_PAGE_ORDER)) { split_free_pages(cc.freepages, gfp_mask); /* Free head and tail (if any) */ @@ -6802,7 +6810,15 @@ int alloc_contig_range_noprof(unsigned l free_contig_range(outer_start, start - outer_start); if (end != outer_end) free_contig_range(end, outer_end - end); - } else if (start == outer_start && end == outer_end && is_power_of_2(end - start)) { + + outer_start = start; + outer_end = end; + + if (!(gfp_mask & __GFP_COMP)) + goto done; + } + + if (start == outer_start && end == outer_end && is_range_aligned) { struct page *head = pfn_to_page(start); int order = ilog2(end - start); _ Patches currently in -mm which might be from tujinjiang@huawei.com are mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch