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 ADB9F242D66 for ; Mon, 15 Sep 2025 22:17:49 +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=1757974669; cv=none; b=N9nDT8WQ53ZlB9B7CfQ70aUgTku6PJKCumGZDEhO2cjz6BrsVMz1cpRIsEZl7stPxNRcw0lYjmDSuCEPDy6+VvXwm8HSvQvL/a6nO8Odh3kHvrqR8fdUoB8yZoEWfbRIc7c5n6xSJK17Qdjk9OlJXNzFXi/5EKk6yRNhhyCnY/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757974669; c=relaxed/simple; bh=dFqreTldrdDnk4QU3tn14q/irM9IzGKY2o8SwZv00pY=; h=Date:To:From:Subject:Message-Id; b=twOcbwZyNyDr4iuBNfWd3qMSTMVvSmvMAh971b9SKPzmwmzd8Ttjfq2WIPXoPcGl2a4c3Qa2Gus+Tjvx9pNF6enRJakaG5RxFryrqqTgydrp3AYS1Qx2p60BFNj0G6D9mnz3dWWTqMSQ9J6QRggRIa5v+EOPkIRHLBVZNlCXy3Q= 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=prBB/FXM; 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="prBB/FXM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32C0AC4CEF1; Mon, 15 Sep 2025 22:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1757974669; bh=dFqreTldrdDnk4QU3tn14q/irM9IzGKY2o8SwZv00pY=; h=Date:To:From:Subject:From; b=prBB/FXMq9eryc74rRNpUBKV7vXtHcIutASIm90RYp4ahx3Lmfh/823qmLdEAiGbR wqxruo0VSOzCbZ79z+eUiU6clXlvIhZh1VhjO8pxttguGj4yCYtbiBN+I0IME13Olz YW3GxsS9XmhZt5POypKOIicy09zcJqSK57nWpTbk= Date: Mon, 15 Sep 2025 15:17:48 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,usamaarif642@gmail.com,souravpanda@google.com,shakeel.butt@linux.dev,pasha.tatashin@soleen.com,kent.overstreet@linux.dev,hannes@cmpxchg.org,00107082@163.com,surenb@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + alloc_tag-avoid-warnings-when-freeing-non-compound-tail-pages.patch added to mm-unstable branch Message-Id: <20250915221749.32C0AC4CEF1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: alloc_tag: avoid warnings when freeing non-compound "tail" pages has been added to the -mm mm-unstable branch. Its filename is alloc_tag-avoid-warnings-when-freeing-non-compound-tail-pages.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alloc_tag-avoid-warnings-when-freeing-non-compound-tail-pages.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: Suren Baghdasaryan Subject: alloc_tag: avoid warnings when freeing non-compound "tail" pages Date: Mon, 15 Sep 2025 14:27:56 -0700 When freeing "tail" pages of a non-compount high-order page, we properly subtract the allocation tag counters, however later when these pages are released, alloc_tag_sub() will issue warnings because tags for these pages are NULL. This issue was originally anticipated by Vlastimil in his review [1] and then recently reported by David. Prevent warnings by marking the tags empty. Link: https://lkml.kernel.org/r/20250915212756.3998938-4-surenb@google.com Link: https://lore.kernel.org/all/6db0f0c8-81cb-4d04-9560-ba73d63db4b8@suse.cz/ [1] Signed-off-by: Suren Baghdasaryan Suggested-by: David Wang <00107082@163.com> Acked-by: Shakeel Butt Cc: Johannes Weiner Cc: Kent Overstreet Cc: Pasha Tatashin Cc: Sourav Panda Cc: Usama Arif Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/page_alloc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/mm/page_alloc.c~alloc_tag-avoid-warnings-when-freeing-non-compound-tail-pages +++ a/mm/page_alloc.c @@ -5240,9 +5240,16 @@ static void ___free_pages(struct page *p __free_frozen_pages(page, order, fpi_flags); else if (!head) { pgalloc_tag_sub_pages(tag, (1 << order) - 1); - while (order-- > 0) + while (order-- > 0) { + /* + * The "tail" pages of this non-compound high-order + * page will have no code tags, so to avoid warnings + * mark them as empty. + */ + clear_page_tag_ref(page + (1 << order)); __free_frozen_pages(page + (1 << order), order, fpi_flags); + } } } _ Patches currently in -mm which might be from surenb@google.com are alloc_tag-use-release_pages-in-the-cleanup-path.patch alloc_tag-prevent-enabling-memory-profiling-if-it-was-shut-down.patch alloc_tag-avoid-warnings-when-freeing-non-compound-tail-pages.patch