1. 29 3月, 2011 1 次提交
    • A
      perf symbols: Fix vsyscall symbol lookup · 6c6804fb
      Andrew Lutomirski 提交于
      Perf can't currently trace into the vsyscall page.  It looks like it was
      meant to work.
      
      Tested on 2.6.38 and today's -git.
      
      The bug is easy to reproduce.  Compile this:
      
      int main()
      {
      	int i;
      	struct timespec t;
      	for(i = 0; i < 10000000; i++)
      		clock_gettime(CLOCK_MONOTONIC, &t);
      	return 0;
      }
      
      and run it through perf record; perf report.  The top entry shows
      "[unknown]" and you can't zoom in.
      
      It looks like there are two issues.  The first is a that a test for user
      mode executing in kernel space is backwards.  (That's the first hunk
      below).  The second (I think) is that something's wrong with the code
      that generates lots of little struct dso objects for different sections
      -- when it runs on vmlinux it results in bogus long_name values which
      cause objdump to fail.
      
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      LPU-Reference: <AANLkTikxSw5+wJZUWNz++nL7mgivCh_Zf=2Kq6=f9Ce_@mail.gmail.com>
      Signed-off-by: NAndy Lutomirski <luto@mit.edu>
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      6c6804fb
  2. 28 3月, 2011 19 次提交
  3. 27 3月, 2011 20 次提交