Messages in this thread | | | Date | Wed, 5 Jul 2023 23:01:02 +0800 | From | Ming Lei <> | Subject | Re: [PATCH v2 1/4] blk-mq: use percpu csd to remote complete instead of per-rq csd |
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On Thu, Jun 29, 2023 at 07:03:56PM +0800, chengming.zhou@linux.dev wrote: > From: Chengming Zhou <zhouchengming@bytedance.com> > > If request need to be completed remotely, we insert it into percpu llist, > and smp_call_function_single_async() if llist is empty previously. > > We don't need to use per-rq csd, percpu csd is enough. And the size of > struct request is decreased by 24 bytes. > > This way is cleaner, and looks correct, given block softirq is guaranteed to be > scheduled to consume the list if one new request is added to this percpu list, > either smp_call_function_single_async() returns -EBUSY or 0. > > Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> > --- > v2: > - Change to use call_single_data_t, which avoid to use 2 cache lines > for 1 csd, as suggested by Ming Lei. > - Improve the commit log, the explanation is copied from Ming Lei.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Thanks, Ming
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