On Tue, Jan 14, 2025 at 03:32:14PM +0100, Peter Zijlstra wrote:
On Tue, Jan 14, 2025 at 01:47:28PM +0100, Florian Schmaus wrote:
While the rebalance thread is isually not compute bound, it does cause
a considerable amount of I/O. Since "reducing" the nice level from 0
to 19, also implicitly reduces the threads best-effort I/O scheduling
class level from 4 to 7, the reblance thread's I/O will be depriotized
over normal I/O.
Furthermore, we set the rebalance thread's scheduling class to BATCH,
which means that it will potentially receive a higher scheduling
latency. Making room for threads that need a low
schedulinglatency (e.g., interactive onces).
sorta.. what worries me most about these patches are the claims without
backing numbers.
Supposedly there is a problem, and this here fixes it, but it doesn't
really get quantified much here.
yeah, it was explained to me and made sense at the time, but things
somehow keep falling out of my overflowing brain.
Florian, could you update the patch message with that? Was it intended
as a partial workaround for the rebalance spinning issue some users have
been hitting?
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