Re: [PATCH] Preemption Latency Measurement Tool

[safemode <safemode@speakeasy.net>]

Is it possible to run the 20 worsst latency thing without having the pre-empt 
patch ?  I'd like to see how things run without the preempt patch and which 
ones are the slowest.   The last time i used the pre-empt patch i had worse 
audio performance than not.  Perhaps that's because i use alsa. 



On Wednesday 19 September 2001 21:40, Ignacio Vazquez-Abrams wrote:
> 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.