From nobody Sat Feb 7 21:08:19 2026 Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (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 569263043BE for ; Fri, 6 Feb 2026 07:22:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770362561; cv=none; b=n8Jom5EirMXJUewDZ3fOkSU7HjcplQHihq+O/emNsupVdKJP1YNwUxk7bVqJzDQPK83DECgXO4Jio5JCc8eOxM7kghtfKhNrOdH6woSL9+5kQku4OyYgEH9K2zQFaeTZpC1gB+5qn14S2B3/3kzGVx16GjHgfIxazRh/gmDkb8Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770362561; c=relaxed/simple; bh=F7W3yiVr/M0UglItoXhkGkH8zbC0c5HRKNf8oOiaVgk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mJVzFObTYlPgfvMFH76SFkELEDAxtygi1UJnpsExgtYa8ZVGlEKgwaib7kg6KylSw9E9OmnF00gyhyogGJNWVcdAt/tfvXOwWETqTQJrdZPbbJOxOioN0dTsOLpZWjLCobz8pD7VXPLuDhruvErhdN69Odx1ucwfxVFWERhcwYo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=kWhW/9Q2; arc=none smtp.client-ip=95.215.58.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="kWhW/9Q2" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1770362559; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FlgnQqPR0Eqtlq7a3B9xxhSsLwOvW1r1+v4iZpc7xIc=; b=kWhW/9Q2R5RI8yTcLIJXaW0F0l2jwPZG+wn3xYTgRi6V2vts0omDsq/CDPphq2QsoFQECt pB69MQnUf5fELBEb3fISrxDsqxbq4Sup6C9qWK5NiqR0+CP+L6VppMGK7XQRDgrd+KCkPl HxmYS3RrMHIqcKlfVnmPms3K/Gs431M= From: Jiayuan Chen To: linux-mm@kvack.org Cc: Jiayuan Chen , Nhat Pham , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Jonathan Corbet , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Yosry Ahmed , Chengming Zhou , Shuah Khan , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v2 1/2] mm: zswap: add per-memcg stat for incompressible pages Date: Fri, 6 Feb 2026 15:22:15 +0800 Message-ID: <20260206072220.144008-2-jiayuan.chen@linux.dev> In-Reply-To: <20260206072220.144008-1-jiayuan.chen@linux.dev> References: <20260206072220.144008-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Jiayuan Chen The global zswap_stored_incompressible_pages counter was added in commit dca4437a5861 ("mm/zswap: store Signed-off-by: Jiayuan Chen Acked-by: Shakeel Butt Reviewed-by: SeongJae Park Reviewed-by: Yosry Ahmed --- Documentation/admin-guide/cgroup-v2.rst | 5 +++++ include/linux/memcontrol.h | 1 + mm/memcontrol.c | 8 ++++++++ 3 files changed, 14 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-= guide/cgroup-v2.rst index 7f5b59d95fce..78a329414615 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1737,6 +1737,11 @@ The following nested keys are defined. zswpwb Number of pages written from zswap to swap. =20 + zswap_incomp + Number of incompressible pages currently stored in zswap + without compression. These pages could not be compressed to + a size smaller than PAGE_SIZE, so they are stored as-is. + thp_fault_alloc (npn) Number of transparent hugepages which were allocated to satisfy a page fault. This counter is not present when CONFIG_TRANSPARENT_HUGEPA= GE diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index b6c82c8f73e1..d8ec05dd5d43 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -39,6 +39,7 @@ enum memcg_stat_item { MEMCG_KMEM, MEMCG_ZSWAP_B, MEMCG_ZSWAPPED, + MEMCG_ZSWAP_INCOMP, MEMCG_NR_STAT, }; =20 diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 007413a53b45..a6b6cf5f1aeb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -341,6 +341,7 @@ static const unsigned int memcg_stat_items[] =3D { MEMCG_KMEM, MEMCG_ZSWAP_B, MEMCG_ZSWAPPED, + MEMCG_ZSWAP_INCOMP, }; =20 #define NR_MEMCG_NODE_STAT_ITEMS ARRAY_SIZE(memcg_node_stat_items) @@ -1346,6 +1347,7 @@ static const struct memory_stat memory_stats[] =3D { #ifdef CONFIG_ZSWAP { "zswap", MEMCG_ZSWAP_B }, { "zswapped", MEMCG_ZSWAPPED }, + { "zswap_incomp", MEMCG_ZSWAP_INCOMP }, #endif { "file_mapped", NR_FILE_MAPPED }, { "file_dirty", NR_FILE_DIRTY }, @@ -5458,6 +5460,9 @@ void obj_cgroup_charge_zswap(struct obj_cgroup *objcg= , size_t size) memcg =3D obj_cgroup_memcg(objcg); mod_memcg_state(memcg, MEMCG_ZSWAP_B, size); mod_memcg_state(memcg, MEMCG_ZSWAPPED, 1); + /* size =3D=3D PAGE_SIZE means compression failed, page is incompressible= */ + if (size =3D=3D PAGE_SIZE) + mod_memcg_state(memcg, MEMCG_ZSWAP_INCOMP, 1); rcu_read_unlock(); } =20 @@ -5481,6 +5486,9 @@ void obj_cgroup_uncharge_zswap(struct obj_cgroup *obj= cg, size_t size) memcg =3D obj_cgroup_memcg(objcg); mod_memcg_state(memcg, MEMCG_ZSWAP_B, -size); mod_memcg_state(memcg, MEMCG_ZSWAPPED, -1); + /* size =3D=3D PAGE_SIZE means compression failed, page is incompressible= */ + if (size =3D=3D PAGE_SIZE) + mod_memcg_state(memcg, MEMCG_ZSWAP_INCOMP, -1); rcu_read_unlock(); } =20 --=20 2.43.0