Re: [RFC][PATCHSET] sanitized pathwalk machinery (v3)

From: Matthew Wilcox
Date: Wed Mar 04 2020 - 08:28:18 EST


On Wed, Mar 04, 2020 at 06:55:47AM +0000, Al Viro wrote:
> On Tue, Mar 03, 2020 at 11:23:39PM -0600, Eric W. Biederman wrote:
> > Do the xfs-tests cover that sort of thing?
> > The emphasis is stress testing the filesystem not the VFS but there is a
> > lot of overlap between the two.
>
> I do run xfstests. But "runs in KVM without visible slowdowns" != "won't
> cause them on 48-core bare metal". And this area (especially when it
> comes to RCU mode) can be, er, interesting in that respect.
>
> FWIW, I'm putting together some litmus tests for pathwalk semantics -
> one of the things I'd like to discuss at LSF; quite a few codepaths
> are simply not touched by anything in xfstests.

Might be more appropriate for LTP than xfstests? will-it-scale might be
the right place for performance benchmarks.