Re: SCHED_IDLE patch is a source of DoS

Andrea Arcangeli (andrea@e-mind.com)
Sun, 8 Nov 1998 15:47:58 +0100 (CET)


On Sun, 8 Nov 1998, Richard Gooch wrote:

>I don't think this "deadlock" is actually a real problem. Unless there
>is some bug in the FS/VFS, a process should not call schedule() while

You mean to do something like:

lock()
CRITICAL-SECTION
/* I should schedule() here but Richard told
me to stall the machine and to loop forever wating for the sync
write to disk */
#ifdef efficient
schedule()
#else
while (not written to disk);
#endif
unlock();

>the FS if schedule() is called with locks held. So, the problem isn't
>with SCHED_IDLE, it's elsewhere.

I am happy for you if you have so many CPU in your machine that you don' t
care about stalling some of them in stupid loop cycle but unfortunately I
have only one CPU my machine.

Andrea Arcangeli

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