summaryrefslogtreecommitdiffstats
path: root/arch/ia64/sn/include
diff options
context:
space:
mode:
authorJack Steiner <steiner@sgi.com>2006-11-22 09:55:08 -0600
committerTony Luck <tony.luck@intel.com>2006-12-12 11:47:09 -0800
commit1cf24bdbbbd2eb5439796dc399ab1649d150ed1d (patch)
treef1ef2033b15e43d01a5759f90130900455ea5957 /arch/ia64/sn/include
parent8b9c106856d92c8266697328b148d115538b59ce (diff)
[IA64] - Reduce overhead of FP exception logging messages
Improve the scalability of the fpswa code that rate-limits logging of messages. There are 2 distinctly different problems in this code. 1) If prctl is used to disable logging, last_time is never updated. The result is that fpu_swa_count is zeroed out on EVERY fp fault. This causes a very very hot cache line. The fix reduces the wallclock time of a 1024p FP exception test from 28734 sec to 19 sec!!! 2) On VERY large systems, excessive messages are logged because multiple cpus can each reset or increment fpu_swa_count at about the same time. The result is that hundreds of messages are logged each second. The fixes reduces the logging rate to ~1 per second. Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/sn/include')
0 files changed, 0 insertions, 0 deletions