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