From: Cyril Hrubis <chrubis@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH] madvise07: Increase probability of testing a supported page type
Date: Wed, 13 Sep 2017 14:44:56 +0200 [thread overview]
Message-ID: <20170913124456.GA28447@rei.lan> (raw)
In-Reply-To: <862571300.14738390.1505297297582.JavaMail.zimbra@redhat.com>
Hi!
> > Wouldn't this mean that the API is broken by desing?
> >
> > One thing is that the call does not work on an unmapped page and fails
> > to return an error. But if we cannot even guarantee that it will work
> > if we make an effort to fault the page in advance its horribly broken by
> > design.
>
> I think Richard was talking about scenario where something happens
> to page you just faulted in, e.g. it's swapped out for some reason.
> That should be quite unlikely.
We can always mlock() the page if that ever happens...
> > > I don't have objections to patch, but I'm thinking if we should go
> > > further if there's possibility the test still won't be reliable.
> > > We could relax the condition, for example by FAILing only if
> > > child dies unexpectedly (signal != SIGBUS).
> >
> > What would that mean, producing TCONF on any error from the madvise()
> > call? Looking at manual pages the only error we may get running
> > MADVISE_HWPOISON as a root on a mapped page is the EINVAL we handle
> > anyway.
>
> I'd stay with just "mmap+touch anonymous memory" for now and see if
> that ever fails.
I've applied the patch from Richard.
--
Cyril Hrubis
chrubis@suse.cz
next prev parent reply other threads:[~2017-09-13 12:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-28 13:48 [LTP] [PATCH] madvise07: Increase probability of testing a supported page type Richard Palethorpe
2017-08-30 7:51 ` Jan Stancek
2017-09-01 12:44 ` Richard Palethorpe
2017-09-12 15:45 ` Cyril Hrubis
2017-09-13 10:08 ` Jan Stancek
2017-09-13 12:44 ` Cyril Hrubis [this message]
2017-09-13 12:45 ` Cyril Hrubis
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