Re: [PATCH] Preemption Latency Measurement Tool

Ignacio Vazquez-Abrams
2001-09-20T01:40:38Z

I'm posting this in the hope that someone will find it useful.

Worst 20 latency times of 4647 measured in this period.
usec cause mask start line/file address end line/file
35735 spin_lock 1 358/memory.c c012c74a 379/memory.c
14003 spin_lock 1 341/vmscan.c c013977b 362/vmscan.c
13701 spin_lock 1 1376/sched.c c0118ef9 697/sched.c
12533 BKL 7 2689/buffer.c c0149acc 697/sched.c
12459 spin_lock 7 547/sched.c c0116ca3 697/sched.c
10479 spin_lock 1 703/vmscan.c c013a213 685/vmscan.c
10443 spin_lock 1 669/inode.c c015e8dd 696/inode.c
9163 reacqBKL 1 1375/sched.c c0118edb 1381/sched.c
8727 BKL 9 164/inode.c c0171885 188/inode.c
8066 usb-uhci d 76/softirq.c c0120cf2 119/softirq.c
8041 BKL 9 130/attr.c c015fbd4 143/attr.c
7982 spin_lock 8 547/sched.c c0116ca3 204/namei.c
6920 reacqBKL 5 1375/sched.c c0118edb 697/sched.c
6720 spin_lock 0 1376/sched.c c0118ef9 1380/sched.c
6567 spin_lock 0 661/vmscan.c c013a0f2 764/vmscan.c
6365 spin_lock 0 703/vmscan.c c013a213 764/vmscan.c
5680 BKL 1 452/exit.c c011f6c6 697/sched.c
5646 spin_lock 0 227/inode.c c015df35 696/inode.c
5428 spin_lock 1 710/inode.c c015ea08 696/inode.c
4933 spin_lock 0 547/sched.c c0116ca3 1380/sched.c

This was taken after compiling several packages and running dbench a few
times.

I also ran it previously while running 'while true ; do python -c range\(3e7\)
; done', and the first line had minimum latencies of 10000, going as high as
about 96000 when swapping.

This is on an Athlon 1050/100 Asus A7V (KT133) with PC133 CL2 SDRAM running
2.4.9-ac12-preempt1.

--
Ignacio Vazquez-Abrams <ignacio@openservices.net>