On 05/25/2017 11:24 AM, Bart Van Assche wrote: > On Thu, 2017-05-25 at 17:09 +0800, Ming Lei wrote: >> Another big issue is that 'srcu_struct' is very big, which shouldn't >> be embedded into hctx, since we only have one real user of >> BLK_MQ_F_BLOCKING. >> >> So I will fix that too. > > Hello Ming, > > Is something like the (untested) patch below perhaps what you had in mind? > > Subject: [PATCH] blk-mq: Reduce blk_mq_hw_ctx size > > Since the srcu structure is rather large (184 bytes on an x86-64 > system), only allocate it if needed. On my normal laptop setup, it's actually 408 bytes (!!). -- Jens Axboe