From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7010118DF80; Fri, 11 Sep 2026 01:23:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789089836; cv=none; b=Rljw5faEwRIdnCobH86yz3Zobkz0Os7STUp3+uyTCe5FrnMCm/2znfBGXThixUrZ7EVQ6LZ3Tx5UBh3VOLSA3JCGoFPrUzSAwtMNlYy2TXrhUzd3JBkk/+1eIeSQp2Xlf0WGx0chFLJGL8SLTf2iDATwo6xuM/NeY2bvs2kNSCU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789089836; c=relaxed/simple; bh=KuRfJQGV6M5WblNNGhdfEaOjFUigjF7Ucc3XXJVic4M=; h=Date:To:From:Subject:Message-Id; b=lTCrJDmS/TUA7cc8M6B8m5ag9zsG28+K3DXXelV1NeXACAV7Fs1xx61vD5EWTihDGukyirFfl3VqGyfBEtMmm64pIT1bWRD+miqET+AXnZiNL4cX6l+L5T1MhoJo/W4aUXQtZIApxkJkN+aRTB1TVDordBp8uoML3iuagQyvjMQ= 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=cpH5Y+Sr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="cpH5Y+Sr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC5B21F000FF; Fri, 11 Sep 2026 01:23:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789089835; bh=TfxO/CxdoT8y8lLRCV6DW+mYA2+pEi4JKNnD9kr7rEQ=; h=Date:To:From:Subject; b=cpH5Y+Sr0umoLA6bK0qkQT221qZRmiHOIbqG1P7CsRF3SQMCPck5jFImIvYDofw9m bvlspwuc+YhtuD/DSY9Fl7y1+do0KKqtZoNlzAvgIgb8VFm04NFM3N2S+tv04NvD0N OKd44W58Cp6d16yQ2jcswzhv4tljDbfpxOXJG1bY= Date: Thu, 10 Sep 2026 18:23:54 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,nphamcs@gmail.com,hannes@cmpxchg.org,chengming.zhou@linux.dev,xialonglong@kylinos.cn,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-zswap-enable-static-key-after-runtime-pool-recovery.patch removed from -mm tree Message-Id: <20260911012354.EC5B21F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/zswap: enable static key after runtime pool recovery has been removed from the -mm tree. Its filename was mm-zswap-enable-static-key-after-runtime-pool-recovery.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Longlong Xia Subject: mm/zswap: enable static key after runtime pool recovery Date: Sat, 5 Sep 2026 20:50:28 +0800 When CONFIG_ZSWAP_DEFAULT_ON is disabled, zswap_setup() can complete without a pool after a failed initial pool creation. A later compressor parameter update can create and publish a pool, but does not enable zswap_ever_enabled. If users then enable zswap, zswap_store() intercepts swapout while zswap_load() still returns -ENOENT without consulting the xarray. The swapin path therefore reads a stale backing swap slot because the store skipped writing it. Enable the static key after a successful compressor and pool update. Do this outside zswap_pools_lock because static key updates may sleep. Verified with fault injection on a stock kernel (compressor builtin, CONFIG_ZSWAP_DEFAULT_ON=n): 1. Boot with zswap.enabled=1; pool creation fails, init completes pool-less (static key off). 2. Echo an available compressor name to zswap.compressor; a pool is recovered but the key stays off. 3. Enable zswap. 4. madvise(MADV_PAGEOUT) a pattern-verified 512 MiB region, then fault it back in and verify. Step 4 reads back 131072/131072 zeroed pages (zswpin=0, zswpout=131072) without this patch; all pages intact (zswpin=131072) with it. Link: https://lore.kernel.org/20260905125101.2970456-1-xialonglong2025@163.com Fixes: 2d4d2b1cfb85 ("mm: zswap: add zswap_never_enabled()") Assisted-by: Zcode:GLM-5.3 Signed-off-by: Longlong Xia Cc: Chengming Zhou Cc: Johannes Weiner Cc: Longlong Xia Cc: Nhat Pham Cc: Signed-off-by: Andrew Morton --- mm/zswap.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/zswap.c~mm-zswap-enable-static-key-after-runtime-pool-recovery +++ a/mm/zswap.c @@ -586,6 +586,9 @@ static int zswap_compressor_param_set(co else ret = -EINVAL; + if (!ret) + static_branch_enable(&zswap_ever_enabled); + spin_lock_bh(&zswap_pools_lock); if (!ret) { _ Patches currently in -mm which might be from xialonglong@kylinos.cn are mm-hugetlb-do-not-dissolve-gigantic-pages-without-runtime-support.patch mm-hugetlb-warn-instead-of-silently-bailing-gigantic-pages-without-runtime-support.patch mm-hugetlb-preserve-source-surplus-accounting-during-demotion.patch mm-hugetlb-cap-demotion-at-currently-available-free-pages.patch mm-zswap-publish-the-initial-pool-with-list_add_rcu.patch mm-zswap-enable-zswap_ever_enabled-in-zswap_pool_create.patch