Messages in this thread | | | Date | Tue, 23 Jan 2018 13:24:24 -0500 (EST) | Subject | Re: [RFC PATCH 0/4] softirq: Per vector threading v3 | From | David Miller <> |
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From: Linus Torvalds <torvalds@linux-foundation.org> Date: Tue, 23 Jan 2018 09:42:32 -0800
> But I wonder if the test triggers the "lets run lots of workqueue > threads", and then the single-threaded user space just gets blown out > of the water by many kernel threads. Each thread gets its own "fair" > amount of CPU, but..
If a single cpu's softirq deferral can end up running on multiple workqueue threads, indeed that's a serious problem.
So if we're in a workqueue and it does a:
schedule_work_on(this_cpu, currently_executing_work);
it'll potentially make a new thread?
That's exactly the code path that will get exercised during a UDP flood the way that vector_work_func() is implemented.
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