From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A0F423DE for ; Fri, 25 Feb 2022 18:03:55 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 5EAE41F44A; Fri, 25 Feb 2022 18:03:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1645812232; h=from:from:reply-to: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=+Yfx6BYjupT6FJvPBiP/J6fWBiTk107w6SeEj7q5Klk=; b=r3D13KGnpbppsRc9ii4T3MVnbZvbDjeh6yA6fQk7REw/+y+ZXzlktrZItPebE7krOc99xc TzS3d3sDIVyPqWxY8Xlgo2aAcTfVNvyWHgYJUcvRHhak60KuhKWhRcuR/vvyW21NeeJIZk t1fQ+KavQ7Bm4nwRAZvFAFB5KqsuVQ8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1645812232; h=from:from:reply-to: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=+Yfx6BYjupT6FJvPBiP/J6fWBiTk107w6SeEj7q5Klk=; b=nVmGh+q4eZWpix4pbXiN1758PxD8VAfz1Am5Gz53Wz110bSoIsAkKRRrdINxdhsApPsSWB CpPYX3D6UBHMulBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2EDE513EA7; Fri, 25 Feb 2022 18:03:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id yKLVCggaGWKSRQAAMHmgww (envelope-from ); Fri, 25 Feb 2022 18:03:52 +0000 From: Vlastimil Babka To: David Rientjes , Christoph Lameter , Joonsoo Kim , Pekka Enberg , Roman Gushchin Cc: Andrew Morton , linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, Oliver Glitta , Faiyaz Mohammed , Vlastimil Babka , Jonathan Corbet , Randy Dunlap , linux-doc@vger.kernel.org Subject: [PATCH 5/5] slab, documentation: add description of debugfs files for SLUB caches Date: Fri, 25 Feb 2022 19:03:18 +0100 Message-Id: <20220225180318.20594-6-vbabka@suse.cz> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220225180318.20594-1-vbabka@suse.cz> References: <20220225180318.20594-1-vbabka@suse.cz> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3076; i=vbabka@suse.cz; h=from:subject; bh=Z5xj7PzTOFSpE0pbr9lBjpkfetxkbHzTO1UejCdWQ8s=; b=owEBbQGS/pANAwAIAeAhynPxiakQAcsmYgBiGRnl7O4Oyi/9lFUUrqVMZhZ+sJjFUodWofVv+pRg xGljxtiJATMEAAEIAB0WIQSNS5MBqTXjGL5IXszgIcpz8YmpEAUCYhkZ5QAKCRDgIcpz8YmpEATlB/ 9C6Oy0ADNsAs+rGleFVl1L9e7F1la8CZjE3ErKtX85TVjMuqT1HKpQ6muldsYcC/SUyUfeArKVLgnM 6Tl6j546wWnlAVosCWzv8VUKAMd38RPN3iqGTDrkAwOi7BipFHg7tFX1qY5ILSKs2otLDQ7I8WjZaf GgvBhm41OPN6BLpLF181bxz19jgTlSJjlXtK7RGlsqfiSO6eCzfgbXo5l1wDbQQqobtl2uUCxeDF0m sw0U3kCDx/dU4NvK/CrsVbqXma1grWuKaXAIMZoDAXaGMRd5YlZjIXn7Ng9BR+lVMj8z1i5GjumQTb gBdgcKqYgjHh9BG8Jz+OCIoZq2xSnJ X-Developer-Key: i=vbabka@suse.cz; a=openpgp; fpr=A940D434992C2E8E99103D50224FA7E7CC82A664 Content-Transfer-Encoding: 8bit From: Oliver Glitta Add description of debugfs files alloc_traces and free_traces to SLUB cache documentation. [ vbabka@suse.cz: some rewording ] Signed-off-by: Oliver Glitta Signed-off-by: Vlastimil Babka Cc: Jonathan Corbet Cc: Randy Dunlap Cc: linux-doc@vger.kernel.org --- Documentation/vm/slub.rst | 61 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/Documentation/vm/slub.rst b/Documentation/vm/slub.rst index d3028554b1e9..2b2b931e59fc 100644 --- a/Documentation/vm/slub.rst +++ b/Documentation/vm/slub.rst @@ -384,5 +384,66 @@ c) Execute ``slabinfo-gnuplot.sh`` in '-t' mode, passing all of the 40,60`` range will plot only samples collected between 40th and 60th seconds). + +DebugFS files for SLUB +====================== + +For more information about current state of SLUB caches with the user tracking +debug option enabled, debugfs files are available, typically under +/sys/kernel/debug/slab// (created only for caches with enabled user +tracking). There are 2 types of these files with the following debug +information: + +1. alloc_traces:: + + Prints information about unique allocation traces of the currently + allocated objects. The output is sorted by frequency of each trace. + + Information in the output: + Number of objects, allocating function, minimal/average/maximal jiffies since alloc, + pid range of the allocating processes, cpu mask of allocating cpus, and stack trace. + + Example::: + + 1085 populate_error_injection_list+0x97/0x110 age=166678/166680/166682 pid=1 cpus=1:: + __slab_alloc+0x6d/0x90 + kmem_cache_alloc_trace+0x2eb/0x300 + populate_error_injection_list+0x97/0x110 + init_error_injection+0x1b/0x71 + do_one_initcall+0x5f/0x2d0 + kernel_init_freeable+0x26f/0x2d7 + kernel_init+0xe/0x118 + ret_from_fork+0x22/0x30 + + +2. free_traces:: + + Prints information about unique free traces of the currently free objects, + sorted by their frequency. + + Information in the output: + Number of objects, freeing function, minimal/average/maximal jiffies since free, + pid range of the freeing processes, cpu mask of freeing cpus, and stack trace. + + Example::: + + 51 acpi_ut_update_ref_count+0x6a6/0x782 age=236886/237027/237772 pid=1 cpus=1 + kfree+0x2db/0x420 + acpi_ut_update_ref_count+0x6a6/0x782 + acpi_ut_update_object_reference+0x1ad/0x234 + acpi_ut_remove_reference+0x7d/0x84 + acpi_rs_get_prt_method_data+0x97/0xd6 + acpi_get_irq_routing_table+0x82/0xc4 + acpi_pci_irq_find_prt_entry+0x8e/0x2e0 + acpi_pci_irq_lookup+0x3a/0x1e0 + acpi_pci_irq_enable+0x77/0x240 + pcibios_enable_device+0x39/0x40 + do_pci_enable_device.part.0+0x5d/0xe0 + pci_enable_device_flags+0xfc/0x120 + pci_enable_device+0x13/0x20 + virtio_pci_probe+0x9e/0x170 + local_pci_probe+0x48/0x80 + pci_device_probe+0x105/0x1c0 + Christoph Lameter, May 30, 2007 Sergey Senozhatsky, October 23, 2015 -- 2.35.1