Re: [PATCHv4 14/17] zsmalloc: make zspage lock preemptible

[Sergey Senozhatsky]

On (25/02/13 16:21), Sergey Senozhatsky wrote:
> BASE
> ====
> 
> 1363.64user 157.08system 1:30.89elapsed 1673%CPU (0avgtext+0avgdata 825692maxresident)k
> 
> lock stats
> 
>                               class name    con-bounces    contentions   waittime-min   waittime-max waittime-total   waittime-avg    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
>                    &pool->migrate_lock-R:             0              0           0.00           0.00           0.00           0.00          10001         702081           0.14         104.74      125571.64           0.18
>                             &class->lock:             1              1           0.25           0.25           0.25           0.25           6320         840542           0.06         809.72      191214.87           0.23
>                          &zspage->lock-R:             0              0           0.00           0.00           0.00           0.00           6452         664129           0.12         660.24      201888.61           0.30
>                 &zram->table[index].lock:             0              0           0.00           0.00           0.00           0.00        1716362        3096466           0.07         811.10      365551.24           0.12
>                             &zstrm->lock:             0              0           0.00           0.00           0.00           0.00              0         664129           1.68        1004.80    14853571.32          22.37
> 
> PATCHED
> =======
> 
> 1366.50user 154.89system 1:30.33elapsed 1684%CPU (0avgtext+0avgdata 825692maxresident)k
> 
> lock stats
> 
>                               class name    con-bounces    contentions   waittime-min   waittime-max waittime-total   waittime-avg    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
>                          &pool->lock#3-R:             0              0           0.00           0.00           0.00           0.00           3648         701979           0.12          44.09      107333.02           0.15
>                             &class->lock:             0              0           0.00           0.00           0.00           0.00           5038         840434           0.06        1245.90      211814.60           0.25
>                          zsmalloc-page-R:             0              0           0.00           0.00           0.00           0.00              0         664078           0.05         699.35      236641.75           0.36
>                         zram-entry->lock:             0              0           0.00           0.00           0.00           0.00              0        3098328           0.06        2987.02      313339.11           0.10
>    &per_cpu_ptr(comp->stream, cpu)->lock:             0              0           0.00           0.00           0.00           0.00             23         664078           1.77        7071.30    14838397.61          22.34

So...

I added lock-stat handling to zspage->lock and to zram (in zram it's only
trylock that we can track, but it doesn't really bother me).  I also
renamed zsmalloc-page-R to old zspage->lock-R and zram-entry->lock to
old zram->table[index].lock, just in case if anyone cares.

Now bounces stats for zspage->lock and zram->table[index].lock look
pretty much like in BASE case.

PATCHED
=======

                              class name    con-bounces    contentions   waittime-min   waittime-max waittime-total   waittime-avg    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
                         &pool->lock#3-R:             0              0           0.00           0.00           0.00           0.00           2702         703841           0.22         873.90      197110.49           0.28
                            &class->lock:             0              0           0.00           0.00           0.00           0.00           4590         842336           0.10        3329.63      256595.70           0.30
                          zspage->lock-R:             0              0           0.00           0.00           0.00           0.00           4750         665011           0.08        3360.60      258402.21           0.39
                 zram->table[index].lock:             0              0           0.00           0.00           0.00           0.00        1722291        3099346           0.12        6943.09      721282.34           0.23
   &per_cpu_ptr(comp->stream, cpu)->lock:             0              0           0.00           0.00           0.00           0.00             23         665011           2.84        7062.18    14896206.16          22.40