Alan Cox wrote:
> 64bit atomic increments are expensive. You can collect the same data via
> ipchains if you wish to take the hit, or sample very 15 minutes

Which reminds me.
Let me know if this "cheap 63bit atomic increment" works...

Increment:

    lock
    addl  $1,counter
    jo    0f
    jc    0f
.section .fixup,"ax"
0:  incl  counter+4
    jmp   1f
.previous
1:

Read:

    movl  counter+4,%edx
    lock
    addl  $0,(%esp)
    movl  counter,%eax
    cmpl  $0x80000000,%eax
    adcl  $0,%edx
    shrl  $1,%edx

Based on the observation that carry events are rare.
We can safely assume two never happen during the processor race windows.

enjoy,
-- Jamie
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