On Fri, Mar 24, 2006 at 12:43:33PM +0100, Blaisorblade wrote:
> We discussed this time ago, and read the description of the patch:
>
> # Also, as suggested by Jeff, remove a redundant enabling of SIGVTALRM,
> # comprised in the subsequent local_irq_enable(). I'm just a bit dubious if
> # ordering matters there...
Oops, nevermind.
> Note this pre-dates soft interrupts, however.
Shouldn't matter.
> > global-ldt-sem - We should be using mutexes now, not semaphores
>
> That's your patch, but below I drop this.
My patch predates mutexes.
But you still use semaphores, and that should be updated.
> > undo-global-ldt-sem - what's so horrible about the global? it won't
> > be highly contended, so making a single mutex saves memory from every
> > ldt.
>
> For memory: 500 existing processes (a huge number in practice) * 20 byte (and
> I think a semaphore is smaller) = 10 Kbyte. We waste more for the kernel
> stack of 1 thread.
>
> For reason: the compilation problem can be avoided differently (and the
> subsequent patch also merges duplicated code).
>
> I didn't like global_ldt_sem because I felt it unclean; if done for memory
> usage it's another story, but still we need to check this creates no locking
> problem (almost surely no, but I want to look at the code well).
It's simpler. A single global lock is simpler than a lock in every
datastructure.
Jeff
-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642
_______________________________________________
User-mode-linux-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
