On Mon, Aug 12, 2019 at 05:02:00PM -0400, Daniel Jordan wrote: > __padata_remove_cpu clears the offlined CPU from the usable masks after > padata_alloc_pd has initialized pd->cpu, which means pd->cpu could be > initialized to this CPU, causing padata to wait indefinitely for the > next job in padata_get_next. > > Make the usable masks reflect the offline CPU when they're established > in padata_setup_cpumasks so pd->cpu is initialized properly. > > Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder") > Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx> > Cc: linux-crypto@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > --- > > Hi, one more edge case. All combinations of CPUs among > parallel_cpumask, serial_cpumask, and CPU hotplug have now been tested > in a 4-CPU VM, and an 8-CPU VM has run with random combinations of these > settings for over an hour. > > kernel/padata.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) If we modify patch 2/2 by calling this after cpu_online_mask has been updated then this problem should go away because we can then remove the cpumask_clear_cpu calls. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt