Messages in this thread |  | | From | Jeff Moyer <> | Subject | Re: [PATCH 4.5/8] blkcg, cfq-iosched: use GFP_NOWAIT instead of GFP_ATOMIC for non-critical allocations | Date | Tue, 09 Jun 2015 10:27:59 -0400 |
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Tejun Heo <tj@kernel.org> writes:
> From b848495d2c987e960d1f7794966d82c05fcefc6d Mon Sep 17 00:00:00 2001 > From: Tejun Heo <tj@kernel.org> > Date: Tue, 9 Jun 2015 13:19:40 +0900 > > blkcg performs several allocations to track IOs per cgroup and enforce > resource control. Most of these allocations are performed lazily on > demand in the IO path and thus can't involve reclaim path. Currently, > these allocations use GFP_ATOMIC; however, blkcg can gracefully deal > with occassional failures of these allocations by punting IOs to the > root cgroup and there's no reason to reach into the emergency reserve. > > This patch replaces GFP_ATOMIC with GFP_NOWAIT for the following > allocations. > > * bdi_writeback_congested and blkcg_gq allocations in blkg_create(). > > * radix tree node allocations for blkcg->blkg_tree. > > * cfq_queue allocation on ioprio changes. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Suggested-by: Jeff Moyer <jmoyer@redhat.com> > Suggested-by: Vivek Goyal <vgoyal@redhat.com>
Thanks, Tejun!
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
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