problems with new the "contigmalloc" routine
Peter Jeremy
PeterJeremy at optushome.com.au
Sat May 21 03:43:11 GMT 2005
On Fri, 2005-May-20 15:56:15 -0700, Don Lewis wrote:
>On 21 May, Peter Jeremy wrote:
>> On Fri, 2005-May-20 21:51:34 +0200, Hans Petter Selasky wrote:
>
>>>Can anyone explain why "uiomove()" has to sleep, and why there is no
>>>non-blocking "uiomove()"?
>>
>> As far as I can see, uiomove() only sleeps if it is asked to do a
>> kernel<->userland move that takes more than twice a scheduler quantum.
>> As long as you don't uiomove() ridiculous amounts of data, it should
>> never sleep.
>
>It can also sleep if it stumbles across a userland page that isn't
>resident. When this happens, it will sleep until the page is retrieved
>from swap.
Mea culpa. I thought pcb_onfault was invoked in lieu of paging but
it's actually invoked after the pager has tried to bring the page in.
--
Peter Jeremy
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