I've tracked the start of the strange instruction pointers in 'perf
report' to a commit by Anton:
commit 75382aa72f06823db7312ad069c3bae2eb3f8548
Author: Anton Blanchard <an...@samba.org>
Date: Tue Jun 26 01:01:36 2012 +0000
powerpc/perf: Move code to select SIAR or pt_regs into perf_read_regs
I don't know enough about PPC to know what's going on, but reverting
the changes to perf_instruction_pointer() gets me reasonable 'perf
report' output with 3.11.
Thanks,
mh
On Thu, Oct 3, 2013 at 10:21 AM, Martin Hicks <m...@bork.org> wrote:
> Hi,
>
> I've been trying to track down a performance regression that started
> leading up to the v3.6 kernel, and while doing this I've been
> gathering perf data on v3.6-rc and comparing it to v3.11 perf reports
> of the same workload.
>
> With v3.6-rc kernels I get all symbols resolved like this:
>
> # Events: 39K cpu-clock-msecs
> #
> # Overhead Command Shared Object
> Symbol
> # ........ ........... ......................
> ........................................
> #
> 9.69% nfsd [kernel.kallsyms] [k] csum_partial
> 5.64% nfsd [kernel.kallsyms] [k] __do_softirq
> 3.12% nfsd [sunrpc] [k] svc_create
> 2.38% nfsd [kernel.kallsyms] [k] __queue_work
> 1.91% nfsd [gianfar_driver] [k] gfar_poll
> 1.73% nfsd [kernel.kallsyms] [k] memset
> 1.54% nfsd [nfsd] [k] nfsd_vfs_read.isra.16
> 1.40% ksoftirqd/0 [kernel.kallsyms] [k]
> finish_task_switch.isra.54
> 1.30% nfsd [kernel.kallsyms] [k] get_page_from_freelist
> 1.21% nfsd [gianfar_driver] [k] gfar_start_xmit
> 1.20% nfsd [sunrpc] [k] svc_xprt_received
>
>
> But when I perf on v3.11 kernels I see a lot of unresolved symbols:
>
> # Events: 69K cpu-clock-msecs
> #
> # Overhead Command Shared Object
> Symbol
> # ........ ............ .....................
> ...................................
> #
> 73.80% nfsd [unknown] [k] 0x7ffff7fa
> 7.57% nfsd [kernel.kallsyms] [k] csum_partial
> 4.59% kworker/0:1 [unknown] [k] 0x7ffff832
> 3.76% ksoftirqd/0 [unknown] [k] 0x7ffff96e
> 0.94% kswapd0 [unknown] [k] 0x7ffffcc2
> 0.92% swapper [unknown] [k] 0x7ffffa54
> 0.62% nfsd [kernel.kallsyms] [k] __udp4_lib_lookup
> 0.49% nfsd [kernel.kallsyms] [k] ip_append_page
> 0.48% nfsd [kernel.kallsyms] [k] __do_softirq
> 0.36% eventmon [unknown] [k] 0x7ffff9c4
> 0.32% nfsd [kernel.kallsyms] [k] __getnstimeofday
>
>
> Any ideas? Have I overlooked some necessary kernel config change?
> Does perf need some binary that I may not have installed on this
> embedded platform?
>
> Freescale mpc8379 (e300c4)
> Gcc-4.7.2 uClibC built with ct-ng 1.18.0
> binutils 2.22
>
> Thanks,
> mh
>
> --
> Martin Hicks P.Eng. | m...@bork.org
> Bork Consulting Inc. | +1 (613) 266-2296
--
Martin Hicks P.Eng. | m...@bork.org
Bork Consulting Inc. | +1 (613) 266-2296
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