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Re: [Qemu-block] [Qemu-devel] [PATCH v2 1/2] block/accounting: introduce
Re: [Qemu-block] [Qemu-devel] [PATCH v2 1/2] block/accounting: introduce latency histogram
Thu, 8 Mar 2018 13:49:51 -0600
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On 03/08/2018 12:58 PM, Vladimir Sementsov-Ogievskiy wrote:
Hm. these numbers are actually boundary points of histogram
intervals, not intervals itself. And, wiki says "The bins are usually
specified as consecutive, non-overlapping intervals of a variable.",
so, intervals are bins.
So, what about:
(and same names with s/_/-/ for qapi)
Any of those works for me; 1 is probably most precise, while 3 is the
shortest to type.
Also, now I doubt, is it a good idea to share same bin boundaries for
each io type.
so, for qmp command, what about:
boundaries - optional, default boundaries for all io operations
boundaries-read - boundaries for read
boundaries-write - boundaries for write
so, call without any boundaries: drop _all_ histograms
call with only specific boundaries-*: set or reset _only_ corresponding
call with only boundaries parameter: set or reset _all_ histograms
call with boundaries parameter and some of (or all, but it is not
useful) specific boundaries-*: set or reset _all_ histograms, some to
default and some to specific.
Seems reasonable, and if that makes the command more useful for your
timing, I'm fine with it (your argument that different timing bins for
read and write also makes sense, as there are some inherent differences
in the amount of work done in the two directions).
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org