Christoph, Darrick could you have a look at this patch please? Andrew has put it into mmotm but I definitely do not want it passes your attention.
On Fri 23-06-17 10:53:42, Michal Hocko wrote: > From: Michal Hocko <mho...@suse.com> > > KM_MAYFAIL didn't have any suitable GFP_FOO counterpart until recently > so it relied on the default page allocator behavior for the given set > of flags. This means that small allocations actually never failed. > > Now that we have __GFP_RETRY_MAYFAIL flag which works independently on the > allocation request size we can map KM_MAYFAIL to it. The allocator will > try as hard as it can to fulfill the request but fails eventually if > the progress cannot be made. It does so without triggering the OOM > killer which can be seen as an improvement because KM_MAYFAIL users > should be able to deal with allocation failures. > > Cc: Darrick J. Wong <darrick.w...@oracle.com> > Cc: Christoph Hellwig <h...@infradead.org> > Signed-off-by: Michal Hocko <mho...@suse.com> > --- > fs/xfs/kmem.h | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/xfs/kmem.h b/fs/xfs/kmem.h > index d6ea520162b2..4d85992d75b2 100644 > --- a/fs/xfs/kmem.h > +++ b/fs/xfs/kmem.h > @@ -54,6 +54,16 @@ kmem_flags_convert(xfs_km_flags_t flags) > lflags &= ~__GFP_FS; > } > > + /* > + * Default page/slab allocator behavior is to retry for ever > + * for small allocations. We can override this behavior by using > + * __GFP_RETRY_MAYFAIL which will tell the allocator to retry as long > + * as it is feasible but rather fail than retry forever for all > + * request sizes. > + */ > + if (flags & KM_MAYFAIL) > + lflags |= __GFP_RETRY_MAYFAIL; > + > if (flags & KM_ZERO) > lflags |= __GFP_ZERO; > > -- > 2.11.0 > -- Michal Hocko SUSE Labs
