Messages in this thread | | | Date | Sun, 7 Nov 1999 19:45:04 +0100 | From | Andi Kleen <> | Subject | Re: [patch] ipc updates |
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On Sun, Nov 07, 1999 at 07:20:08PM +0100, Manfred Spraul wrote: > Andi Kleen wrote: > > > > As far as I can see it still has the resource race (resources are charged > > after sleeping without rechecking, so there is a window where the user is > > able to overcommit). Here is for reference my 2.2 patch that fixes the > > problem and Scott Maxwell's DoS. > > > > I think my patch solves both problems: > * the overcommit race does not exist: the code never sleeps between > checking for free queue space and increasing q_cbytes.
Yes, sorry, seems I misread your new code.
> I reuse the number of bytes in the queue. This allows the user to > overcommit by ~ 3%, IMHO that's acceptable. > (16384 one byte messages eat ~ 512 kB kernel memory, 2 8 Kb message + > 16382 0 byte messages around 528 kB) >
That's a lot. Hopefully Linux will have the beancounter patches someday.
-Andi
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