[RFC PATCH 0/2] softirq: Per vector threading

From: Frederic Weisbecker
Date: Fri Jan 12 2018 - 00:36:11 EST


So this is a first shot to implement what Linus suggested.
To summarize: when a softirq vector is stormed and needs more time than
what IRQ tail can offer, the whole softirq processing is offloaded to
ksoftirqd. But this has an impact on other softirq vectors that are
then subject to scheduler latencies.

So the softirqs time limits is now per vector and only the vectors that
get stormed are offloaded to a thread (workqueue).

This is in a very Proof of concept state. It doesn't even boot successfully
once in a while. So I'll do more debugging tomorrow (today in fact) but
you get the big picture.

It probably won't come free given the clock reads around softirq callbacks.

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
softirq/poc

HEAD: 0e982634115283710d0801048e5a316def26f31d

Thanks,
Frederic
---

Frederic Weisbecker (2):
softirq: Account time and iteration stats per vector
softirq: Per vector thread deferment


kernel/softirq.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 114 insertions(+), 9 deletions(-)