Re: [PATCH] Add tracepoints to track pagecache transition

KOSAKI Motohiro
2009-02-20T01:17:36Z

Hi

> > > Currently, we can understand the amount of pagecache from "Cached"
> > > in /proc/meminfo. So I'd like to understand which files are using pagecache.
> >
> > There is one meta question, Why do you think file-by-file pagecache
> > infomartion is valueable?
>
> One might take a look at Marcello Tosatti's old 'vmtrace' patch. It
> contains it's own data store/transport via relayfs, but the trace points
> could be ported to the current kernel tracing infrastructure.
>
> Here's a starting point: http://linux-mm.org/VmTrace
>
> Quoting from that page:
>
> >From the previous email to linux-mm:
> >"The sequence of pages which a given process or workload accesses
> >during its lifetime, a.k.a. "reference trace", is very important
> >information. It has been used in the past for comparison of page
> >replacement algorithms and other optimizations..."

Sure.
but strong difference exist.

vmtrace
- can run standalone
- reviewer can confirm its output result is useful or not.

Christoph also explained reason more kindly.
I think we need useful consumer.