Messages in this thread | | | Date | Wed, 30 Nov 2011 09:18:03 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH 3/9] readahead: record readahead patterns |
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On Wed, Nov 30, 2011 at 01:57:43AM +0800, Andi Kleen wrote: > On Tue, Nov 29, 2011 at 09:09:03PM +0800, Wu Fengguang wrote: > > Record the readahead pattern in ra->pattern and extend the ra_submit() > > parameters, to be used by the next readahead tracing/stats patches. > > I like this, could it be exported it a bit more formally in /proc for > each file descriptor?
Something like this?
$ cat /proc/self/fdinfo/2 pos: 0 flags: 0100002 + ra_pattern: initial + ra_size: 4
It may be some rapidly changing information, however in practical should remain stable unless it's changing access pattern a lot.
> I could imagine a monitoring tool that you run on a process that > tells you what pattern state the various file descriptors are in and how > large the window is. That would be similar to the tools for > monitoring network connections, which are extremly useful > in practice.
Yeah, the simplest form may be
watch "head /proc/self/fdinfo/*"
Thanks, Fengguang
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