An error occurred fetching the project authors.
  1. 12 Nov, 2008 2 commits
    • Steven Rostedt's avatar
      trace: rename unlikely profiler to branch profiler · 2ed84eeb
      Steven Rostedt authored
      Impact: name change of unlikely tracer and profiler
      
      Ingo Molnar suggested changing the config from UNLIKELY_PROFILE
      to BRANCH_PROFILING. I never did like the "unlikely" name so I
      went one step farther, and renamed all the unlikely configurations
      to a "BRANCH" variant.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      2ed84eeb
    • Ingo Molnar's avatar
      tracing: branch tracer, fix vdso crash · 2b7d0390
      Ingo Molnar authored
      Impact: fix bootup crash
      
      the branch tracer missed arch/x86/vdso/vclock_gettime.c from
      disabling tracing, which caused such bootup crashes:
      
        [  201.840097] init[1]: segfault at 7fffed3fe7c0 ip 00007fffed3fea2e sp 000077
      
      also clean up the ugly ifdefs in arch/x86/kernel/vsyscall_64.c by
      creating DISABLE_UNLIKELY_PROFILE facility for code to turn off
      instrumentation on a per file basis.
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      2b7d0390
  2. 23 May, 2008 2 commits
  3. 30 Jan, 2008 1 commit
  4. 11 Oct, 2007 1 commit
  5. 12 Sep, 2007 1 commit
  6. 22 Jul, 2007 1 commit
    • Andi Kleen's avatar
      x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu · 2aae950b
      Andi Kleen authored
      This implements new vDSO for x86-64.  The concept is similar
      to the existing vDSOs on i386 and PPC.  x86-64 has had static
      vsyscalls before,  but these are not flexible enough anymore.
      
      A vDSO is a ELF shared library supplied by the kernel that is mapped into
      user address space.  The vDSO mapping is randomized for each process
      for security reasons.
      
      Doing this was needed for clock_gettime, because clock_gettime
      always needs a syscall fallback and having one at a fixed
      address would have made buffer overflow exploits too easy to write.
      
      The vdso can be disabled with vdso=0
      
      It currently includes a new gettimeofday implemention and optimized
      clock_gettime(). The gettimeofday implementation is slightly faster
      than the one in the old vsyscall.  clock_gettime is significantly faster
      than the syscall for CLOCK_MONOTONIC and CLOCK_REALTIME.
      
      The new calls are generally faster than the old vsyscall.
      
      Advantages over the old x86-64 vsyscalls:
      - Extensible
      - Randomized
      - Cleaner
      - Easier to virtualize (the old static address range previously causes
      overhead e.g. for Xen because it has to create special page tables for it)
      
      Weak points:
      - glibc support still to be written
      
      The VM interface is partly based on Ingo Molnar's i386 version.
      
      Includes compile fix from Joachim Deguara
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2aae950b