Added by Mathieu Desnoyers over 11 years ago. Updated over 11 years ago.
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Description
Currently, per-uid buffers use the same default subbuffer size as per-pid buffers, but it does not make sense to use this value, since the reason for having small per-pid buffers (that we have typically many pids in a system) does not apply to per-uid buffers.
Any suggestions ?
It depends on so much "unknown" variables such as the throughput, number of apps, number of events, ...
We can go 4 or 8 times bigger? Tbh, either a wild guest or we do a survey to our users. :)
I'm tempted to derive the size based on the values we use for kernel tracing, and divide that value e.g. by 2, assuming we can have typically up to 2 users tracing in a system.
Thoughts ?
Thanks,
Mathieu
Mathieu Desnoyers wrote:
I'm tempted to derive the size based on the values we use for kernel tracing, and divide that value e.g. by 2, assuming we can have typically up to 2 users tracing in a system.
This would make sense for defining the default value. However, would it be a separate entry in defaults.h?
Yes, we'd split the current UST default entries into UST_PID and
UST_UID.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
Yah most probably it will be a default value specific to per UID buffers.
So the Kernel size is: 262144 bytes so dividing this by two makes: 131072 bytes --> 128K
Seems good as any other values to me :)
Applied in changeset 0a9c649428b2ea8d4e743aebc12585eeb58fcf64.