Messages in this thread | | | Date | Thu, 30 Aug 2018 09:29:40 +0200 | From | Vincent Whitchurch <> | Subject | Re: [PATCH 2/2] scripts: add kmemleak2pprof.py for slab usage analysis |
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On Tue, Aug 28, 2018 at 04:28:04PM -0700, Andrew Morton wrote: > On Tue, 28 Aug 2018 12:39:14 +0200 Vincent Whitchurch <vincent.whitchurch@axis.com> wrote: > > > Add a script which converts /sys/kernel/debug/kmemleak_all to the pprof > > format, which can be used for analysing memory usage. See > > https://github.com/google/pprof. > > Why is this better than /proc/slabinfo?
slabinfo just tells you how much memory is being used in a particular slab, it doesn't give you a breakdown of who allocated all that memory. slabinfo can't also tell you how much memory a particular subsystem is using.
For example, here we can see that tracer_init_tracefs() and its callers are using ~12% of the total tracked memory:
$ pprof -top -compact_labels -cum prof Showing nodes accounting for 13418.95kB, 92.07% of 14575.28kB total Dropped 4069 nodes (cum <= 72.88kB) flat flat% sum% cum cum% ... 0 0% 56.71% 1832.15kB 12.57% tracer_init_tracefs+0x74/0x1cc
And that tracefs' dentrys use 500 KiB and its inodes use 1+ MiB:
$ pprof -text -compact_labels -focus tracer_init_tracefs -nodecount 2 prof Main binary filename not available. Showing nodes accounting for 1794.85kB, 12.31% of 14575.28kB total Dropped 1912 nodes (cum <= 72.88kB) Showing top 2 nodes out of 32 flat flat% sum% cum cum% 1294.56kB 8.88% 8.88% 1294.56kB 8.88% new_inode_pseudo+0x8/0x4c 500.29kB 3.43% 12.31% 500.29kB 3.43% d_alloc+0x10/0x78 ...
> > > $ ./kmemleak2pprof.py kmemleak_all > > $ pprof -text -ignore free_area_init_node -compact_labels -nodecount 10 prof > > Are we missing an argument here? s/prof/kmemleak_all/?
No, the default output filename of this script is called "prof".
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