Messages in this thread | | | Date | Mon, 6 Oct 2008 22:16:50 +0200 | From | Heiko Carstens <> | Subject | Re: [PATCH/RFC 0/4] Add stop_machine_get/put_threads to stop_machine infrastructrue. |
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On Mon, Oct 06, 2008 at 02:42:40PM +1000, Rusty Russell wrote: > On Friday 03 October 2008 20:56:32 you wrote: > > However we need to be able to do that without allocating any memory. > > Nice work Heiko! > > See free_module(), which calls stop_machine and, well, just hopes it works. > So we've needed this for a while.
Ah, good. At least there is one other user then :)
> > Patch 1 is a stop_machine bugfix and is independent of the rest > Hmm, do you actually need this? It was a whim (and clearly a dumb one). I'm > tempted to change it to: > > err = smdata->fn(smdata->data); > if (err) > smdata->fnret = err;
That looks much better than the cmpxchg loop I came up with. All we need to know is that 'something' went wrong. Any return code != 0 should be enough.
> > Patch 2 introduces the new proposed interface > > Could we just encapsulate the threads etc. into a "struct stopmachine" which > is returned from stop_machine_prepare(), then implement everything in terms > of that?
You mean that we put the pointers to the threads, the cpu mask, etc. in this structure, instead of wasting bss size? That would be just a kmalloc call in __stop_machine_get_threads(). Or do you think of something different?
Anyway, I'm going to send a hopefully better patch tommorrow.
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