Re: [Announce] Development release 0.1 of the LatencyTOP tool

From: Arjan van de Ven
Date: Sat Jan 19 2008 - 00:25:42 EST


Andi Kleen wrote:
yes indeed; I sort of use the same infrastructure inside the scheduler; the biggest
reason I felt I had to do something different was that I wanted to do per process
data collection, so that you can see for a specific process what was going on.

Wouldn't it have been easier then to just extend the sleep profiler to
oprofile? oprofile already has pid filters and can do per process profiling.

it's more complex than that

On the other hand I'm not fully sure only doing per pid profiling
is that useful. After all often latencies come from asynchronous
threads (like kblockd). So a system level view is probably better
anyways.

another thing that the current profiling can't do, is to show what the system is doing
when it hits the latency.. so someone calling fsync() will show up in the waiting for
IO function, but not that it was due to an fsync().
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