From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=13.76.78.106 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794535991; b=ij+ypZ1LZCBB1pENCRUimva9WhLOc+9dvnDgYuous6YGL2/il1Xnp2xBBrMITrnIJX0O rlEuAQCjpPwLwpcWzOhDF27vVT3AW802BesE3J7iYEWUBiX0DwPh6/MkorZJAm+xsKtvz kq3S1Y1HAmQVo+yq5LHCsP43digMLOG7nFE4Ca2yILUtZpr3snkstOFT6/1xZeAUtDC7a hlIuCYbJYz29/J5i7+Fy0MRsGvyS3XZncnyFw/QcpwrOT/7a5UW7k+e81djsN9oUlkudA tJwwXT0FqhrpJBz9kFk4Fnk2fD0rajMrfrqYpxihwesEJ208TOOwyrm/9k6Rj+BTw2Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794535991; h=DMARC-Filter:Received:Received:Message-ID:Date:MIME-Version: User-Agent:Subject:To:Cc:References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding:X-CM-TRANSID:X-Coremail-Antispam: X-CM-SenderInfo; bh=2Y84LlsZe6rgvKsWJlLFsVqJRljJBA8w4SWbN4DVpek=; b=mfLVgUFGMpRNQL9BrKcYgMYmNU8W7xzJ7o5uul7axofs88zMNhUceLEAgZxPxjVCt8lD hau4jYNdA7xcJUcNuTeVpa+hlbPw669rmQ30JiC+NCmEUKVDQXj2/UkKnKgUvn5pxDvaR oX0f4Fl2G69VXDleH4y4ePBf4yuS0Q/7Uh3zpXkWS+ynUnHyjbyVePzPM8VnNNYDbmQgM vr2/mb0R1nZ9Zw4mp51k7RcWPs/da4SgFc11bsbOeqObs+ssf2yUZp+xkyp0Zj9FegOtx CfENUiNzIiNr5HvQYx+tcF9Hqju77HEh1E2t0fN2hmcj/aCRtNrc1EnjyXdBpxwJ7ug== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=hust.edu.cn; spf=pass smtp.mailfrom=hust.edu.cn; arc=none smtp.remote-ip=13.76.78.106 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [13.76.78.106]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DAE7A606A323; Fri, 13 Nov 2026 02:13:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org DAE7A606A323 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=hust.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hust.edu.cn Received: from hust.edu.cn (unknown [172.16.0.50]) by app1 (Coremail) with UTF8SMTP id IAEQrMCmbGgqcvZqjcZEAA--.42040S2; Fri, 13 Nov 2026 10:12:58 +0800 (CST) Received: from [100.81.40.43] (unknown [10.12.191.55]) by gateway (Coremail) with SMTP id _____wC3sN8gcvZqqfo_AA--.64337S2; Fri, 13 Nov 2026 10:12:53 +0800 (CST) Message-ID: Date: Fri, 13 Nov 2026 10:12:47 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3] mm/zsmalloc: remove CONFIG_ZSMALLOC_STAT To: Xueyuan Chen , Minchan Kim , Sergey Senozhatsky , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Shuah Khan , Randy Dunlap , Alex Shi , Yanteng Si , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Helen Koike , Vignesh Raman , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, dri-devel@lists.freedesktop.org, Nhat Pham References: <20261111-zsmalloc_stat-v3-1-2d85ed51570e@gmail.com> From: Dongliang Mu In-Reply-To: <20261111-zsmalloc_stat-v3-1-2d85ed51570e@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:IAEQrMCmbGgqcvZqjcZEAA--.42040S2 Authentication-Results: app1; spf=neutral smtp.mail=dzm91@hust.edu.cn; X-Coremail-Antispam: 1UD129KBjvJXoW3AF17KrWUuF48AF4DZw1DJrb_yoWfGFy3pa 18Jr4xCryxtF15J3yUArykur9xt3ZrWFW8Gw1DW34rZFn2yw4FyFyDKryYv3yDXrWkAa1x GF9agFna93Wjy3JanT9S1TB71UUUU87qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUQEb7Iv0xC_KF4lb4IE77IF4wAFc2x0x2IEx4CE42xK8VAvwI8I cIk0rVWrJVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjx v20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK 6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1ln4kS14v26r 4a6rW5M2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI 12xvs2x26I8E6xACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj64x0Y40En7xvr7AKxV W8Jr0_Cr1UMcIj6x8ErcxFaVAv8VW8uFyUJr1UMcIj6xkF7I0En7xvr7AKxVW8Jr0_Cr1U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwCY1x0262kKe7AKxVW8ZVWrXwCY02 Avz4vE-syl42xK82IYc2Ij64vIr41l42xK82IY6x8ErcxFaVAv8VW8uFyUJr1UMxC20s02 6xCaFVCjc4AY6r1j6r4UMxCIbckI1I0E14v26r1q6r43MI8I3I0E5I8CrVAFwI0_Jr0_Jr 4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWrXVW8Jr1lIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr 1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvE x4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07bY0edUUUUU= X-CM-SenderInfo: asqsiiirqrkko6kx23oohg3hdfq/ On 11/11/26 8:41 PM, Xueyuan Chen wrote: > CONFIG_ZSMALLOC_STAT only controls the debugfs interface. The class > counters are updated regardless of this option. > > Remove the CONFIG_ZSMALLOC_STAT guards and rely on the debugfs API > stubs when CONFIG_DEBUG_FS=n. Skip statistics setup silently when > debugfs is unavailable. > > Remove the Kconfig entry and replace the existing CONFIG_ZSMALLOC_STAT > settings with CONFIG_DEBUG_FS=y. Update the English and Chinese > documentation to match, and clarify the pool name in the debugfs path. > > Suggested-by: Nhat Pham > Reviewed-by: Nhat Pham > Signed-off-by: Xueyuan Chen |The documentation changes look good to me. Acked-by: Dongliang Mu # Documentation| > --- > Drop CONFIG_ZSMALLOC_STAT instead of making the counters conditional. The > option only controls the debugfs interface, while the class counters are > updated unconditionally. Removing it simplifies the code. > > Following Nhat's suggestion, remove CONFIG_ZSMALLOC_STAT and rely on > the existing debugfs API stubs when CONFIG_DEBUG_FS=n. > --- > Changes in v3: > - Squash the three patches into one (Nhat, Sergey). > - Add Nhat's Reviewed-by. > - Update the documentation wording. > - Link to v2: https://patch.msgid.link/20261109-zsmalloc_stat-v2-0-caee41684aba@gmail.com > > Changes in v2: > - Drop CONFIG_ZSMALLOC_STAT instead of making the counters conditional. > - Update configuration files and documentation. > - Link to v1: https://patch.msgid.link/20261106-zsmalloc_stat-v1-1-b574f4714adf@gmail.com > --- > Documentation/mm/zsmalloc.rst | 4 +-- > Documentation/translations/zh_CN/mm/zsmalloc.rst | 2 +- > arch/s390/configs/debug_defconfig | 2 +- > arch/s390/configs/defconfig | 2 +- > drivers/gpu/drm/ci/arm.config | 2 +- > drivers/gpu/drm/ci/arm64.config | 2 +- > drivers/gpu/drm/ci/x86_64.config | 2 +- > mm/Kconfig | 9 ------- > mm/zsmalloc.c | 33 ++---------------------- > 9 files changed, 10 insertions(+), 48 deletions(-) > > diff --git a/Documentation/mm/zsmalloc.rst b/Documentation/mm/zsmalloc.rst > index d2bbecd78e14..4c0786378dc3 100644 > --- a/Documentation/mm/zsmalloc.rst > +++ b/Documentation/mm/zsmalloc.rst > @@ -33,8 +33,8 @@ proper handle-based APIs. > stat > ==== > > -With CONFIG_ZSMALLOC_STAT, we could see zsmalloc internal information via > -``/sys/kernel/debug/zsmalloc/``. Here is a sample of stat output:: > +With CONFIG_DEBUG_FS, we could see zsmalloc internal information via > +``/sys/kernel/debug/zsmalloc/``. Here is a sample of stat output:: > > # cat /sys/kernel/debug/zsmalloc/zram0/classes > > diff --git a/Documentation/translations/zh_CN/mm/zsmalloc.rst b/Documentation/translations/zh_CN/mm/zsmalloc.rst > index 4c8c9b1006a9..b555a07ac871 100644 > --- a/Documentation/translations/zh_CN/mm/zsmalloc.rst > +++ b/Documentation/translations/zh_CN/mm/zsmalloc.rst > @@ -32,7 +32,7 @@ zs_unmap_object()解除映射。 > stat > ==== > > -通过CONFIG_ZSMALLOC_STAT，我们可以通过 ``/sys/kernel/debug/zsmalloc/`` > +启用CONFIG_DEBUG_FS，我们可以通过 ``/sys/kernel/debug/zsmalloc/`` > 看到zsmalloc内部信息。下面是一个统计输出的例子。:: > > # cat /sys/kernel/debug/zsmalloc/zram0/classes > diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig > index d44674b63715..83193ef8efb9 100644 > --- a/arch/s390/configs/debug_defconfig > +++ b/arch/s390/configs/debug_defconfig > @@ -100,7 +100,7 @@ CONFIG_UNIXWARE_DISKLABEL=y > CONFIG_IOSCHED_BFQ=y > CONFIG_BINFMT_MISC=m > CONFIG_ZSWAP=y > -CONFIG_ZSMALLOC_STAT=y > +CONFIG_DEBUG_FS=y > CONFIG_SLAB_BUCKETS=y > CONFIG_SLUB_STATS=y > # CONFIG_COMPAT_BRK is not set > diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig > index e00e252d4694..694a309377d5 100644 > --- a/arch/s390/configs/defconfig > +++ b/arch/s390/configs/defconfig > @@ -94,7 +94,7 @@ CONFIG_UNIXWARE_DISKLABEL=y > CONFIG_IOSCHED_BFQ=y > CONFIG_BINFMT_MISC=m > CONFIG_ZSWAP=y > -CONFIG_ZSMALLOC_STAT=y > +CONFIG_DEBUG_FS=y > CONFIG_SLAB_BUCKETS=y > # CONFIG_COMPAT_BRK is not set > CONFIG_MEMORY_HOTPLUG=y > diff --git a/drivers/gpu/drm/ci/arm.config b/drivers/gpu/drm/ci/arm.config > index d7c51670da2f..fc0a8a4bfb18 100644 > --- a/drivers/gpu/drm/ci/arm.config > +++ b/drivers/gpu/drm/ci/arm.config > @@ -5,7 +5,7 @@ CONFIG_CRYPTO_ZSTD=y > CONFIG_ZRAM_MEMORY_TRACKING=y > CONFIG_ZRAM_WRITEBACK=y > CONFIG_ZRAM=y > -CONFIG_ZSMALLOC_STAT=y > +CONFIG_DEBUG_FS=y > > # abootimg with a 'dummy' rootfs fails with root=/dev/nfs > CONFIG_BLK_DEV_INITRD=n > diff --git a/drivers/gpu/drm/ci/arm64.config b/drivers/gpu/drm/ci/arm64.config > index c46125c1f80f..10b01b55a66d 100644 > --- a/drivers/gpu/drm/ci/arm64.config > +++ b/drivers/gpu/drm/ci/arm64.config > @@ -5,7 +5,7 @@ CONFIG_CRYPTO_ZSTD=y > CONFIG_ZRAM_MEMORY_TRACKING=y > CONFIG_ZRAM_WRITEBACK=y > CONFIG_ZRAM=y > -CONFIG_ZSMALLOC_STAT=y > +CONFIG_DEBUG_FS=y > > # abootimg with a 'dummy' rootfs fails with root=/dev/nfs > CONFIG_BLK_DEV_INITRD=n > diff --git a/drivers/gpu/drm/ci/x86_64.config b/drivers/gpu/drm/ci/x86_64.config > index 7ac98a78691e..8225b806dad8 100644 > --- a/drivers/gpu/drm/ci/x86_64.config > +++ b/drivers/gpu/drm/ci/x86_64.config > @@ -5,7 +5,7 @@ CONFIG_CRYPTO_ZSTD=y > CONFIG_ZRAM_MEMORY_TRACKING=y > CONFIG_ZRAM_WRITEBACK=y > CONFIG_ZRAM=y > -CONFIG_ZSMALLOC_STAT=y > +CONFIG_DEBUG_FS=y > > CONFIG_PWM=y > CONFIG_PM_DEVFREQ=y > diff --git a/mm/Kconfig b/mm/Kconfig > index afff1b25b543..4a77cda7f1d7 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -130,15 +130,6 @@ menu "Zsmalloc allocator options" > > comment "Zsmalloc is a common backend allocator for zswap & zram" > > -config ZSMALLOC_STAT > - bool "Export zsmalloc statistics" > - select DEBUG_FS > - help > - This option enables code in the zsmalloc to collect various > - statistics about what's happening in zsmalloc and exports that > - information to userspace via debugfs. > - If unsure, say N. > - > config ZSMALLOC_CHAIN_SIZE > int "Maximum number of physical pages per-zspage" > default 8 > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index 7ef80e0da626..104ccf3aa170 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -222,9 +222,7 @@ struct zs_size_stat { > unsigned long objs[NR_CLASS_STAT_TYPES]; > }; > > -#ifdef CONFIG_ZSMALLOC_STAT > static struct dentry *zs_stat_root; > -#endif > > static size_t huge_class_size; > > @@ -279,9 +277,7 @@ struct zs_pool { > /* Compact classes */ > struct shrinker *shrinker; > > -#ifdef CONFIG_ZSMALLOC_STAT > struct dentry *stat_dentry; > -#endif > #ifdef CONFIG_COMPACTION > struct work_struct free_work; > #endif > @@ -565,14 +561,10 @@ static inline unsigned long class_stat_read(struct size_class *class, int type) > return class->stats.objs[type]; > } > > -#ifdef CONFIG_ZSMALLOC_STAT > - > static void __init zs_stat_init(void) > { > - if (!debugfs_initialized()) { > - pr_warn("debugfs not available, stat dir not created\n"); > + if (!debugfs_initialized()) > return; > - } > > zs_stat_root = debugfs_create_dir("zsmalloc", NULL); > } > @@ -650,10 +642,8 @@ DEFINE_SHOW_ATTRIBUTE(zs_stats_size); > > static void zs_pool_stat_create(struct zs_pool *pool, const char *name) > { > - if (!zs_stat_root) { > - pr_warn("no root stat dir, not creating <%s> stat dir\n", name); > + if (IS_ERR_OR_NULL(zs_stat_root)) > return; > - } > > pool->stat_dentry = debugfs_create_dir(name, zs_stat_root); > > @@ -666,25 +656,6 @@ static void zs_pool_stat_destroy(struct zs_pool *pool) > debugfs_remove_recursive(pool->stat_dentry); > } > > -#else /* CONFIG_ZSMALLOC_STAT */ > -static void __init zs_stat_init(void) > -{ > -} > - > -static void __exit zs_stat_exit(void) > -{ > -} > - > -static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name) > -{ > -} > - > -static inline void zs_pool_stat_destroy(struct zs_pool *pool) > -{ > -} > -#endif > - > - > /* > * For each size class, zspages are divided into different groups > * depending on their usage ratio. This function returns fullness > > --- > base-commit: fa4ad798f6f681031775266044ba1b0cf3c670bd > > -- > Best regards, > Xueyuan