Messages in this thread | | | Date | Tue, 31 Aug 2010 16:21:14 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64 |
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On Mon, Aug 30, 2010 at 09:31:50PM -0400, Steven Rostedt wrote: > On Wed, 2010-08-25 at 11:32 +1000, Anton Blanchard wrote: > > save_stack_trace() stores the instruction pointer, not the function > > descriptor. On ppc64 the trace stack code currently dereferences the > > instruction pointer and shows 8 bytes of instructions in our backtraces: > > > > # cat /sys/kernel/debug/tracing/stack_trace > > Depth Size Location (26 entries) > > ----- ---- -------- > > 0) 5424 112 0x6000000048000004 > > 1) 5312 160 0x60000000ebad01b0 > > 2) 5152 160 0x2c23000041c20030 > > 3) 4992 240 0x600000007c781b79 > > 4) 4752 160 0xe84100284800000c > > 5) 4592 192 0x600000002fa30000 > > 6) 4400 256 0x7f1800347b7407e0 > > 7) 4144 208 0xe89f0108f87f0070 > > 8) 3936 272 0xe84100282fa30000 > > > > Since we aren't dealing with function descriptors, use %pS instead of %pF > > to fix it: > > > > # cat /sys/kernel/debug/tracing/stack_trace > > Depth Size Location (26 entries) > > ----- ---- -------- > > 0) 5424 112 ftrace_call+0x4/0x8 > > 1) 5312 160 .current_io_context+0x28/0x74 > > 2) 5152 160 .get_io_context+0x48/0xa0 > > 3) 4992 240 .cfq_set_request+0x94/0x4c4 > > 4) 4752 160 .elv_set_request+0x60/0x84 > > 5) 4592 192 .get_request+0x2d4/0x468 > > 6) 4400 256 .get_request_wait+0x7c/0x258 > > 7) 4144 208 .__make_request+0x49c/0x610 > > 8) 3936 272 .generic_make_request+0x390/0x434 > > > > Signed-off-by: Anton Blanchard <anton@samba.org> > > Thanks, I'll test this to make sure it doesn't break x86, and then push > it into a stable/-rc patch queue. > > -- Steve
Ingo has applied it already in perf/urgent.
Thanks.
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