rr-debugger / rr-debugger/rr

Consider restoring don't-preempt-SYS_write-until-k-ms optimization

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Dominant language
C++
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Description

As part of #7, I'm ripping out the code that previously disabled preemption for write but up to a "grace period". write will soon be a buffered syscall and we'll usually not even get a trace event for it; this is optimal. And even if it is preempted, we'll be able to near-optimally resume it.

So the previous optimization would only apply to the (hopefully!) rare case when the syscall buffer is full.

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Research direction

Start by reviewing the changes associated with #7 and locating the code for the previous don't-preempt-SYS_write-until-k-ms optimization. Determine how buffered write syscalls and full syscall buffers affect preemption, then establish whether restoring the optimization is worthwhile for that rare full-buffer case.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, linux
Domain
operating-systems, performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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