On 07/03/14 18:46, Or Gerlitz wrote: > On Thu, Jul 3, 2014 at 4:48 PM, Bart Van Assche <bvanass...@acm.org> wrote: > [...] >> >> Limit the number of poll cycles per completion notification to preserve >> fairness > > [...] > > Any reason not to make use of the block layer NAPI like API for that > (blk-iopoll http://lwn.net/Articles/346187/) ?
Hello Or, As you maybe remember about four years ago I have been experimenting with adding blk-iopoll support in the SRP initiator. What I learned at that time is that the blk-iopoll framework defers work to softirq context. This means that a context switch from interrupt to softirq context has to occur before SRP completion processing can start. Recent measurements on current hardware have shown that such a context switch takes about 0.5 microseconds. Since I prefer to keep the latency of SRP I/O as low as possible I haven't looked further into using blk-iopoll for the SRP initiator driver. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
