Chris Mason wrote:
>On Mon, 2003-06-09 at 19:51, Nick Piggin wrote:
>>>The latency results are better, with average time spent in
>>>__get_request_wait being around 28 jiffies, and a max of 170 jiffies.
>>>The cost is throughput, further benchmarking needs to be done but, but I
>>>wanted to get this out for review and testing. It should at least help
>>>us decide if the request allocation code really is causing our problems.
>>Well the latency numbers are good - is this with dbench 90?
>Yes, that number was dbench 90, but dbench 50,90, and 120 gave about the
>same stats with the final patch.
>>>+static inline int queue_full(request_queue_t *q, int rw)
>>>+ if (rw == READ)
>>>+ return q->read_full;
>>>+ return q->write_full;
>>I don't think you need the barriers here, do you?
>I put the barriers in early on when almost all the calls were done
>outside spin locks, the current flavor of the patch only does one
>clear_queue_full without the io_request_lock held. It should be enough
>to toss a barrier in just that one spot. But I wanted to leave them in
>so I could move things around until the final version (if there ever is
Yeah I see.
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This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:22 EST