From: Oliver Glitta <[email protected]>
Add description of debugfs files alloc_traces and free_traces
to SLUB cache documentation.
[ [email protected]: some rewording ]
Signed-off-by: Oliver Glitta <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: [email protected]
---
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
On Wed, Mar 02, 2022 at 06:31:22PM +0100, Vlastimil Babka wrote:
> From: Oliver Glitta <[email protected]>
>
> Add description of debugfs files alloc_traces and free_traces
> to SLUB cache documentation.
>
> [ [email protected]: some rewording ]
>
> Signed-off-by: Oliver Glitta <[email protected]>
> Signed-off-by: Vlastimil Babka <[email protected]>
> Cc: Jonathan Corbet <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: [email protected]
> ---
> 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 <[email protected]>
> Christoph Lameter, May 30, 2007
> Sergey Senozhatsky, October 23, 2015
> --
> 2.35.1
>
--
Thank you, You are awesome!
Hyeonggon :-)
On Wed, Mar 02, 2022 at 06:31:22PM +0100, Vlastimil Babka wrote:
> From: Oliver Glitta <[email protected]>
>
> Add description of debugfs files alloc_traces and free_traces
> to SLUB cache documentation.
>
> [ [email protected]: some rewording ]
>
> Signed-off-by: Oliver Glitta <[email protected]>
> Signed-off-by: Vlastimil Babka <[email protected]>
> Cc: Jonathan Corbet <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: [email protected]
Acked-by: Mike Rapoport <[email protected]>
> ---
> 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.