On 6/18/19 12:41 PM, Song Liu wrote:
On Mon, Jun 17, 2019 at 8:41 PM Guoqing Jiang <gqjiang@xxxxxxxx> wrote:
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+};
Have we measured the performance overhead of this?
The linear search for every IO worries me.
From array's view, I think the performance will not be impacted,
because write IO is complete
after it reached all the non-writemostly devices.
Hmm... How about the cpu utilization rate? Have you got chance
to do some simple benchmarking?
I can't see the impact of cpu in simple test, because it really depends on
how slow the writemostly device is.
And the modern multi-queue device (also flagged as writemostly) would
be fast enough to handle the write-behind IO in time, which means there
should only a few (or zero) elements in wb_list, but it is a potential issue
which need to be addressed.
Thanks,
Guoqing
