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 AAFD532D0C2 for ; Mon, 15 Dec 2025 20:32:42 +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=1765830762; cv=none; b=REiKPEKVdzK8TZY5o1A6bTIK0RaX+TALii5UTMXPtVx+WmozBZ5NwlLCvmXY+2wlf/r0e4zlaib0EWX3DJwLJ+k0ruNThwyo3DXQFkVtqeB+C8rxgilmlsRzu9i4gKixu7Oqu51hUMo5EZ3BC046NHNa3mvRK00SRaeQNe+E+A4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765830762; c=relaxed/simple; bh=ung3899I4A5xRMtgiJFkQ34Z4qku7r9AWl4BY5KcBUo=; h=Date:To:From:Subject:Message-Id; b=iihNwyjOwAzWGtp9aRP3yvakfV2Z9jDToy53BqGyrff2fJreWwU4De9rD4RnC/nZvXgzum2C/JxNJE9ksr4ltnb+iSMR5dlihfUPaPz0F1mVEmI6QKsYyK6CgJAURYwg8HltEKotY3Ne8htCsjhEEykJIFTvYECPfnIkgqirp0s= 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=zCWSBx/b; 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="zCWSBx/b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC22FC4CEF5; Mon, 15 Dec 2025 20:32:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1765830762; bh=ung3899I4A5xRMtgiJFkQ34Z4qku7r9AWl4BY5KcBUo=; h=Date:To:From:Subject:From; b=zCWSBx/bMx3koXgyUW0Idy5Q/uJ9v4HrQYBEsUuVNziof1XRx9Z36WtCNrVoUfb+l aSmnyF48qDCLNuO9GdhiVuXrREI2p2jFeSwq1G1Mht5l0wFe2dF+/G105sIHfHrTrV 2bMJH6pReexQCAb2MYYDE2fi4b21IrYEJO76BQlk= Date: Mon, 15 Dec 2025 12:32:41 -0800 To: mm-commits@vger.kernel.org,hughd@google.com,baolin.wang@linux.alibaba.com,tongweilin@linux.alibaba.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-shmem-add-mthp-swpout-fallback-statistics-in-shmem_writeout.patch added to mm-new branch Message-Id: <20251215203241.EC22FC4CEF5@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/shmem: add mTHP swpout fallback statistics in shmem_writeout() has been added to the -mm mm-new branch. Its filename is mm-shmem-add-mthp-swpout-fallback-statistics-in-shmem_writeout.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shmem-add-mthp-swpout-fallback-statistics-in-shmem_writeout.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. 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: Weilin Tong Subject: mm/shmem: add mTHP swpout fallback statistics in shmem_writeout() Date: Mon, 15 Dec 2025 10:46:32 +0800 Currently, when shmem mTHPs are split and swapped out via shmem_writeout(), there are no unified statistics to trace these mTHP swpout fallback events. This makes it difficult to analyze the prevalence of mTHP splitting and fallback during swap operations, which is important for memory diagnostics. Here we add statistics counting for mTHP fallback to small pages when splitting and swapping out in shmem_writeout(). Link: https://lkml.kernel.org/r/20251215024632.250149-1-tongweilin@linux.alibaba.com Signed-off-by: Weilin Tong Reviewed-by: Baolin Wang Cc: Hugh Dickins Signed-off-by: Andrew Morton --- mm/shmem.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/mm/shmem.c~mm-shmem-add-mthp-swpout-fallback-statistics-in-shmem_writeout +++ a/mm/shmem.c @@ -1593,11 +1593,23 @@ int shmem_writeout(struct folio *folio, } if (split) { + int order; + try_split: + order = folio_order(folio); /* Ensure the subpages are still dirty */ folio_test_set_dirty(folio); if (split_folio_to_list(folio, folio_list)) goto redirty; + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (order >= HPAGE_PMD_ORDER) { + count_memcg_folio_events(folio, THP_SWPOUT_FALLBACK, 1); + count_vm_event(THP_SWPOUT_FALLBACK); + } +#endif + count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK); + folio_clear_dirty(folio); } _ Patches currently in -mm which might be from tongweilin@linux.alibaba.com are mm-shmem-add-mthp-swpout-fallback-statistics-in-shmem_writeout.patch