Messages in this thread | | | Subject | Re: Poll about irqsafe_cpu_add and others | From | Eric Dumazet <> | Date | Thu, 17 Mar 2011 19:29:29 +0100 |
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Le jeudi 17 mars 2011 à 12:46 -0500, Christoph Lameter a écrit : > On Thu, 17 Mar 2011, Eric Dumazet wrote: > > > When we know we run from BH context, we can use __this_cpu_inc(), but if > > we dont know or run from user/process context, we would need irqsafe_inc > > variant. > > If the BH context is the only one where we care about performance then its > ok I would think.
Hmm... yes.
By the way, I noticed :
DECLARE_PER_CPU(u64, xt_u64); __this_cpu_add(xt_u64, 2) translates to following x86_32 code :
mov $xt_u64,%eax add %fs:0x0,%eax addl $0x2,(%eax) adcl $0x0,0x4(%eax)
I wonder why we dont use :
addl $0x2,%fs:xt_u64 addcl $0x0,%fs:xt_u64+4
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