From: Brad Walker <bwalker-WlSugiYO8JFBDgjK7y7TUQ@public.gmane.org>
To: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: problem w/ read caching..
Date: Mon, 1 Oct 2012 20:56:21 +0000 (UTC) [thread overview]
Message-ID: <loom.20121001T223817-249@post.gmane.org> (raw)
In-Reply-To: 20121001203706.GB26488@google.com
Kent Overstreet <koverstreet@...> writes:
>
> On Mon, Oct 01, 2012 at 08:05:14PM +0000, Brad Walker wrote:
> > Kent Overstreet <koverstreet@...> writes:
> >
> > >
> > > What about cache_bypass_hits, cache_bypass_misses?
> > >
> >
> > cache_bypass_hits = 0
> > cache_bypass_misses = 0
>
> I should've just asked you for all the stats - what about
> cache_miss_collision?
bwalker:/sys/fs/bcache/dd10d09c-0605-462c-af85-8466b0aa2017/stats_total> ls
bypassed cache_bypass_misses cache_hits cache_misses
cache_bypass_hits cache_hit_ratio cache_miss_collisions cache_readaheads
bwalker:/sys/fs/bcache/dd10d09c-0605-462c-af85-8466b0aa2017/stats_total> cat *
0
0
0
98
162315691
0
2329081
0
bwalker:/sys/fs/bcache/dd10d09c-0605-462c-af85-8466b0aa2017/stats_total>
> Also, internal/cache_read_races?
cat /sys/fs/bcache/dd10d09c-0605-462c-af85-8466b0aa2017/interna/cache_read_races
0
> Perhaps stuff is getting evicted from the cache for some reason... How
> big is the SSD?
nellis: # sg_inq /dev/rssda
ATA device: model, serial number and firmware revision:
Micron P320h-MTFDGAR350SAH 000000001143020287B2 B1490300
nellis: # fdisk /dev/rssda
The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.
Command (m for help): p
Disk /dev/rssda: 350.1 GB, 350078754816 bytes
210 heads, 56 sectors/track, 58141 cylinders, total 683747568 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x16e1596f
Device Boot Start End Blocks Id System
/dev/rssda1 2048 683747567 341872760 83 Linux
Command (m for help):
> Is cache_replacement_policy lru? (the default - cache_replacement_policy
> is in cache0/)
LRU
> What's cache0/priority_stats say?
>
nellis: # cat priority_stats
Unused: 97%
Metadata: 0%
Average: 0
Sectors per Q: 582336
Quantiles: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1]
nellis: #
next prev parent reply other threads:[~2012-10-01 20:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-12 20:01 problem w/ read caching Brad Walker
[not found] ` <CAPKZHbV3n7O+VRVNS-C2oDVSpO_VdirMDUOuwwWKaA5ZOUEG_g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-09-13 18:43 ` Kent Overstreet
2012-09-27 23:28 ` Brad Walker
[not found] ` <loom.20120928T010314-562-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2012-09-28 18:59 ` Kent Overstreet
2012-10-01 19:18 ` Brad Walker
[not found] ` <loom.20121001T211315-779-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2012-10-01 19:38 ` Kent Overstreet
2012-10-01 20:05 ` Brad Walker
[not found] ` <loom.20121001T220412-225-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2012-10-01 20:37 ` Kent Overstreet
2012-10-01 20:56 ` Brad Walker [this message]
[not found] ` <loom.20121001T223817-249-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2012-10-01 21:14 ` Kent Overstreet
2012-10-01 22:26 ` Brad Walker
[not found] ` <loom.20121002T001556-394-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2012-10-01 23:00 ` Kent Overstreet
[not found] ` <20121001230023.GG26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-03 4:44 ` Kent Overstreet
2012-10-08 16:39 ` Brad Walker
[not found] <50651c68.a8e1440a.1165.67c8SMTPIN_ADDED@mx.google.com>
[not found] ` <50651c68.a8e1440a.1165.67c8SMTPIN_ADDED-ATjtLOhZ0NVl57MIdRCFDg@public.gmane.org>
2012-09-28 16:31 ` Brad Walker
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