On Thu 10-03-16 16:47:16, Vlastimil Babka wrote: > On 02/29/2016 02:26 PM, Michal Hocko wrote: > >From: Michal Hocko <mhocko@xxxxxxxx> > > > >This is the first step in making mmap_sem write holders killable. It > > s/holders/waiters/? right. Fixed > >focuses on the trivial ones which are taking the lock early after > >entering the syscall and they are not changing state before. > > > >Therefore it is very easy to change them to use down_write_killable > >and immediately return with -EINTR. This will allow the waiter to > >pass away without blocking the mmap_sem which might be required to > >make a forward progress. E.g. the oom reaper will need the lock for > >reading to dismantle the OOM victim address space. > > > >The only tricky function in this patch is vm_mmap_pgoff which has many > >call sites via vm_mmap. To reduce the risk keep vm_mmap with the > >original non-killable semantic for now. > > > >vm_munmap callers do not bother checking the return value so open code > >it into the munmap syscall path for now for simplicity. > > > >Cc: Mel Gorman <mgorman@xxxxxxx> > >Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > >Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx> > >Cc: Hugh Dickins <hughd@xxxxxxxxxx> > >Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> > >Cc: David Rientjes <rientjes@xxxxxxxxxx> > >Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > >Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > >Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> > > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
