Messages in this thread | | | Date | Thu, 18 Jun 2009 20:32:34 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: problem with function_graph self-test? |
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On Thu, 18 Jun 2009, Jeremy Fitzhardinge wrote: > > > > This is something that gcc is screwing with us. After spending all day > > today trying to figure out what is happening, I finally found it in the > > assembly. > > > > In the timer_stats_update_stats function, I get this at the beginning: > > > > 00000327 <timer_stats_update_stats>: > > 327: 57 push %edi > > 328: 8d 7c 24 08 lea 0x8(%esp),%edi > > 32c: 83 e4 e0 and $0xffffffe0,%esp > > 32f: ff 77 fc pushl 0xfffffffc(%edi) > > 332: 55 push %ebp > > 333: 89 e5 mov %esp,%ebp > > 335: 57 push %edi > > 336: 56 push %esi > > 337: 53 push %ebx > > 338: 81 ec 8c 00 00 00 sub $0x8c,%esp > > 33e: e8 fc ff ff ff call 33f <timer_stats_update_stats+0x18> > > 33f: R_386_PC32 mcount > > > > > > And this at the end of the function: > > > > 4f6: 8d 67 f8 lea 0xfffffff8(%edi),%esp > > 4f9: 5f pop %edi > > 4fa: c3 ret > > > > Something to do with using _RET_IP_ in spin_unlock_irqrestore() perhaps?
No, it was the fact that there was a local variable of type struct entry, where entry was defined to be ____cacheline_aligned_in_smp. But that was not the end of it. It happens throughout the code. The next hit was in tcp_ack(). But it has something to do with -Os on i386.
-- Steve
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