Subject: Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch
From: Ingo Molnar (mingo_AT_elte.hu)
Date: Fri Jul 23 2004 - 10:21:27 EEST
* Nick Piggin <nickpiggin_AT_yahoo.com.au> wrote:
> You wouldn't need to do this to break out of interrupt context
> softirqs because you wouldn't bother returning to it. Just hand the
> work off to ksoftirqd.
this is plainly not the case. Look at eg. the net_tx_action() lock-break
i did in the -I1 patch. There we first create a private queue which we
work down. With my approach we can freely reschedule _within the loop_.
With your suggestion this is not possible.
i.e. executing a softirq in a process context gives us all the
advantages of a process context: all the local state is saved and
preserved until the preemption is done. These advantages are not there
for either immediate or idle-task-only-immediate type of softirq
processing.
Ingo
This archive was generated by hypermail 2b28 : Fri Jul 30 2004 - 10:30:32 EEST