[Bug runtime/10665] backtrace() is too slow

["wcohen at redhat dot com" <sourceware-bugzilla at sourceware dot org>]

------- Additional Comments From wcohen at redhat dot com  2009-09-18 21:56 -------
Created an attachment (id=4214)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=4214&action=view)
Non-probe-skipping skript

Here are the timing results for the slow non-working version and the
fast version with the backtrace() removed.

$ stap -v /tmp/latencytap5slow.stp
...
Pass 5: starting run.
WARNING: Number of errors: 0, skipped probes: 101
WARNING: Skipped due to global 'this_sleep' lock timeout: 101
Starting data collection
mode - All Pids

probe kernel.trace("deactivate_task")!+1 (/tmp/latencytap5slow.stp:16:1), hits:
92, cycles: 936min/2159avg/5841max
probe kernel.trace("activate_task")!+1 (/tmp/latencytap5slow.stp:25:1), hits:
96, cycles: 1377min/232381avg/575271max
probe scheduler.cpu_on (/tmp/latencytap5slow.stp:38:1), hits: 131, cycles:
648min/1898954avg/33218154max
probe begin (/tmp/latencytap5slow.stp:60:1), hits: 1, cycles:
4833min/4833avg/4833max
Pass 5: run completed in 20usr/60sys/623real ms.



$ stap -vt /tmp/latencytap5fast.stp 
...
Pass 5: starting run.
Starting data collection
mode - All Pids

^C
7413 354619 7388 0x0000000000000000 
probe kernel.trace("deactivate_task")!+1 (/tmp/latencytap5fast.stp:16:1), hits:
7500, cycles: 783min/3600avg/11097max
probe kernel.trace("activate_task")!+1 (/tmp/latencytap5fast.stp:25:1), hits:
7486, cycles: 936min/4534avg/11673max
probe scheduler.cpu_on (/tmp/latencytap5fast.stp:38:1), hits: 11855, cycles:
405min/1507avg/5787max
probe end (/tmp/latencytap5fast.stp:48:1), hits: 1, cycles:
44577min/44577avg/44577max
probe begin (/tmp/latencytap5fast.stp:60:1), hits: 1, cycles:
3483min/3483avg/3483max
Pass 5: run completed in 10usr/50sys/9150real ms.


-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=10665

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.