Re: [PATCH] VFS: Add VFS event counter infrastructure

From: Andi Kleen
Date: Sat May 21 2011 - 22:24:56 EST

Any comments on where I placed the counters?

> > This patch implements a simple per CPU counter framework for the VFS.
> > The counters are per CPU and are very little overhead. The counters
> > are output in debugfs (/sys/kernel/fs/vfsstat)
> WTF? Since when had debugfs become mandatory?

What do you mean? It's not mandatory of course.

I had it originally in /proc, but then moved it to debugfs.

> > + fs = debugfs_create_dir("fs", NULL);
> > + if (fs)
> > + debugfs_create_file("vfsstat", 0444, fs, NULL, &vfsstat_fops);
> > + return 0;
> Note that if that FPOS is configured away debugfs_create_dir() does _NOT_
> return NULL - you get ERR_PTR(-ENODEV).

That's fine because debugfs_create_file is a noop then too
and fs isn't used anywhere else.


ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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