Re: [PATCH 3/5] blk-mq: fix plugging in blk_sq_make_request

2015-05-01 Thread Jeff Moyer
Christoph Hellwig writes: >> -if (use_plug && !blk_queue_nomerges(q) && >> +if (likely(!is_flush_fua) && !blk_queue_nomerges(q) && > > Please don't sprinkle likely annotations for no go reason. Especially > on metadata write heavy workloads (e.g. an NFS server) it might be very > likely.

Re: [PATCH 3/5] blk-mq: fix plugging in blk_sq_make_request

2015-05-01 Thread Christoph Hellwig
> - if (use_plug && !blk_queue_nomerges(q) && > + if (likely(!is_flush_fua) && !blk_queue_nomerges(q) && Please don't sprinkle likely annotations for no go reason. Especially on metadata write heavy workloads (e.g. an NFS server) it might be very likely. -- To unsubscribe from this list:

[PATCH 3/5] blk-mq: fix plugging in blk_sq_make_request

2015-04-30 Thread Shaohua Li
From: Jeff Moyer The following appears in blk_sq_make_request: /* * If we have multiple hardware queues, just go directly to * one of those for sync IO. */ We clearly don't have multiple hardware queues, here! This comment was introduced with this commit 0706