* Re: [PATCH v2 6/6] slab, documentation: add description of debugfs files for SLUB caches
2022-03-02 17:31 ` [PATCH v2 6/6] slab, documentation: add description of debugfs files for SLUB caches Vlastimil Babka
@ 2022-03-03 8:14 ` Hyeonggon Yoo
2022-03-03 9:33 ` Mike Rapoport
1 sibling, 0 replies; 3+ messages in thread
From: Hyeonggon Yoo @ 2022-03-03 8:14 UTC (permalink / raw)
To: Vlastimil Babka
Cc: David Rientjes, Christoph Lameter, Joonsoo Kim, Pekka Enberg,
Roman Gushchin, Andrew Morton, linux-mm, patches, linux-kernel,
Oliver Glitta, Faiyaz Mohammed, Marco Elver, Mike Rapoport,
Imran Khan, Jonathan Corbet, Randy Dunlap, linux-doc
On Wed, Mar 02, 2022 at 06:31:22PM +0100, Vlastimil Babka wrote:
> From: Oliver Glitta <glittao@gmail.com>
>
> Add description of debugfs files alloc_traces and free_traces
> to SLUB cache documentation.
>
> [ vbabka@suse.cz: some rewording ]
>
> Signed-off-by: Oliver Glitta <glittao@gmail.com>
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: linux-doc@vger.kernel.org
> ---
> Documentation/vm/slub.rst | 64 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 64 insertions(+)
>
> diff --git a/Documentation/vm/slub.rst b/Documentation/vm/slub.rst
> index d3028554b1e9..43063ade737a 100644
> --- a/Documentation/vm/slub.rst
> +++ b/Documentation/vm/slub.rst
> @@ -384,5 +384,69 @@ 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/<cache>/ (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 freeing traces of the currently allocated
> + objects. The freeing traces thus come from the previous life-cycle of the
> + objects and are reported as not available for objects allocated for the first
> + time. The output is sorted by frequency of each trace.
> +
> + 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:::
> +
> + 1980 <not-available> age=4294912290 pid=0 cpus=0
> + 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
> +
Looks very good.
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> Christoph Lameter, May 30, 2007
> Sergey Senozhatsky, October 23, 2015
> --
> 2.35.1
>
--
Thank you, You are awesome!
Hyeonggon :-)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 6/6] slab, documentation: add description of debugfs files for SLUB caches
2022-03-02 17:31 ` [PATCH v2 6/6] slab, documentation: add description of debugfs files for SLUB caches Vlastimil Babka
2022-03-03 8:14 ` Hyeonggon Yoo
@ 2022-03-03 9:33 ` Mike Rapoport
1 sibling, 0 replies; 3+ messages in thread
From: Mike Rapoport @ 2022-03-03 9:33 UTC (permalink / raw)
To: Vlastimil Babka
Cc: David Rientjes, Christoph Lameter, Joonsoo Kim, Pekka Enberg,
Roman Gushchin, Andrew Morton, linux-mm, patches, linux-kernel,
Oliver Glitta, Faiyaz Mohammed, Marco Elver, Hyeonggon Yoo,
Imran Khan, Jonathan Corbet, Randy Dunlap, linux-doc
On Wed, Mar 02, 2022 at 06:31:22PM +0100, Vlastimil Babka wrote:
> From: Oliver Glitta <glittao@gmail.com>
>
> Add description of debugfs files alloc_traces and free_traces
> to SLUB cache documentation.
>
> [ vbabka@suse.cz: some rewording ]
>
> Signed-off-by: Oliver Glitta <glittao@gmail.com>
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: linux-doc@vger.kernel.org
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
> Documentation/vm/slub.rst | 64 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 64 insertions(+)
>
> diff --git a/Documentation/vm/slub.rst b/Documentation/vm/slub.rst
> index d3028554b1e9..43063ade737a 100644
> --- a/Documentation/vm/slub.rst
> +++ b/Documentation/vm/slub.rst
> @@ -384,5 +384,69 @@ 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/<cache>/ (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 freeing traces of the currently allocated
> + objects. The freeing traces thus come from the previous life-cycle of the
> + objects and are reported as not available for objects allocated for the first
> + time. The output is sorted by frequency of each trace.
> +
> + 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:::
> +
> + 1980 <not-available> age=4294912290 pid=0 cpus=0
> + 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
>
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 3+ messages in thread