Re: [PATCH 0 of 4] Generic AIO by scheduling stacks

From: Zach Brown
Date: Wed Jan 31 2007 - 12:38:59 EST


- We would now have some measure of task_struct concurrency. Read that twice,
it's scary.

That's the one scaring me in fact ... Maybe it will end up being an easy
one but I don't feel too comfortable...

Indeed, that was my first reaction too. I dismissed the idea for a good six months after initially realizing that it implied sharing journal_info, etc.

But when I finally sat down and started digging through the task_struct members and, after quickly dismissing involuntary preemption of the fibrils, it didn't seem so bad. I haven't done an exhaustive audit yet (and I won't advocate merging until I have) but I haven't seen any train wrecks.

we didn't create fibril-like
things for threads, instead, we share PIDs between tasks. I wonder if
the sane approach would be to actually create task structs (or have a
pool of them pre-created sitting there for performances) and add a way
to share the necessary bits so that syscalls can be run on those
spin-offs.

Maybe, if it comes to that. I have some hopes that sharing by default and explicitly marking the bits that we shouldn't share will be good enough.

- z
-
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