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
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