On Sat, Jan 23, 2021 at 06:09:11PM -0800, Andrew Morton wrote: > On Fri, 22 Jan 2021 01:37:14 -0300 Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> wrote: > > > Mike Rapoport <rppt@xxxxxxxxxx> writes: > > > > > > Signed-off-by: Roman Gushchin <guro@xxxxxx> > > > > > > Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > I've seen a couple of spurious triggers of the WARN_ONCE() removed by this > > patch. This happens on some ppc64le bare metal (powernv) server machines with > > CONFIG_SWIOTLB=y and crashkernel=4G, as described in a candidate patch I posted > > to solve this issue in a different way: > > > > https://lore.kernel.org/linuxppc-dev/20201218062103.76102-1-bauerman@xxxxxxxxxxxxx/ > > > > Since this patch solves that problem, is it possible to include it in the next > > feasible v5.11-rcX, with the following tag? > > We could do this, if we're confident that this patch doesn't depend on > [1/2] "mm: cma: allocate cma areas bottom-up"? I think it is... A think it does not depend on cma bottom-up allocation, it's rather the other way around: without this CMA bottom-up allocation could fail with KASLR enabled. Still, this patch may need updates to the way x86 does early reservations: https://lore.kernel.org/lkml/20210115083255.12744-1-rppt@xxxxxxxxxx > > Fixes: 8fabc623238e ("powerpc: Ensure that swiotlb buffer is allocated from low memory") > > I added that. > > -- Sincerely yours, Mike.