Messages in this thread |  | | Date | Wed, 14 Feb 2007 15:34:38 -0500 | From | Benjamin LaHaise <> | Subject | Re: [patch 06/11] syslets: core, documentation |
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On Wed, Feb 14, 2007 at 12:14:29PM -0800, Davide Libenzi wrote: > I think you may have mis-interpreted my words. *When* a schedule would > block a synco execution try, then you do have a context switch. Noone > argue that, and the code is clear. The sys_async_exec thread will block, > and a newly woke up thread will re-emerge to sys_async_exec with a NULL > returned to userspace. But in a "cachehit" case (no schedule happens > during the syscall/*let execution), there is no context switch at all. > That is the whole point of the optimization.
And I will repeat myself: that cannot be done. Tell me how the following what if scenario works: you're in an MMX optimized memory copy and you take a page fault. How does returning to the submittor of the async operation get the correct MMX state restored? It doesn't.
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