On Fri 24-05-19 17:43:04, Daniel Jordan wrote: > [ Adding linux-api and some of the people who were involved in the > MCL_ONFAULT/mlock2/etc discussions. Author of the Fixes patch appears to > have moved on. ] > > On Wed, May 22, 2019 at 11:23:37AM +0000, Potyra, Stefan wrote: > > If mlockall() is called with only MCL_ONFAULT as flag, > > it removes any previously applied lockings and does > > nothing else. > > The change looks reasonable. Hard to imagine any application relies on it, and > they really shouldn't be if they are. Debian codesearch turned up only a few > cases where stress-ng was doing this for unknown reasons[1] and this change > isn't gonna break those. In this case I think changing the syscall's behavior > is justified. > > > This behavior is counter-intuitive and doesn't match the > > Linux man page. > > I'd quote it for the changelog: > > For mlockall(): > > EINVAL Unknown flags were specified or MCL_ONFAULT was specified with‐ > out either MCL_FUTURE or MCL_CURRENT. > > With that you can add > > Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > > [1] https://sources.debian.org/src/stress-ng/0.09.50-1/stress-mlock.c/?hl=203#L203 Well spotted and the fix looks reasonable as well. Quoting the man page seems useful as well. Acked-by: Michal Hocko <mhocko@xxxxxxxx> Thanks! -- Michal Hocko SUSE Labs
