[LTP] [PATCH v1] mmapstress06: TCONF on systems without swap space

Petr Vorel pvorel@suse.cz
Wed Apr 29 08:10:43 CEST 2026


> On Tue, Apr 28, 2026 at 06:34:15PM +0200, Petr Vorel wrote:
> > Hi all,

> > > Hi all,

> > > > mmapstress06 is designed to stress the mfile_swap kernel primitive, which
> > Uh, I overlooked "mfile_swap kernel primitive". Then the approach would make
> > sense, but is it really true? mfile_swap does not exist any more, not even in a
> > git log. Test was added in January 2003, e.g. even before 2.6.

> > > > manages shared anonymous memory. On architectures with large pages (like
> > > > 64KB on ppc64le), the test's hardcoded request for 32769 pages results
> > > > in a ~2GB mapping. So in suse test system configured with 2GB of RAM and
> > > > no swap space, the test will fails with following information:

> > I'm not really sure. if that's caused by missing swap or would it work on
> > machine with RAM big enough which has swap disabled (I guess you retest with
> > e.g. 8 GB RAM). Otherwise I'd prefer prefer to deal with errno ENOMEM (12)
> > instead (as I pointed out previously).


> Base description/implementation of test case, The original test is "passive," merely creating a 
> mapping and relying on external processes to trigger swapping(case has sleep_time parameter).
> Further more, this case is "ghost test" for current kernel, it do mmap but never 
> writes to it, so kernel never actually allocated memory, 
> Together with current obsolete logic(test targets legcy mfile_swap) i suggest just delete 
> it instead of wasting time patching(refactor) it. What do you think? @Petr @wang li?

I'm ok with deleting, but i hope others will have look on it as well.

Kind regards,
Petr


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