path: root/arch/powerpc/include/asm
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authorAnton Blanchard <anton@samba.org>2011-03-20 15:28:03 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-03-30 10:44:18 +1100
commitad5d1c888e556bc00c4e86f452cad4a3a87d22c1 (patch)
tree540f1ba66e7ecb8b7a71d64fb1a468867a1890a8 /arch/powerpc/include/asm
parent2d86938a4eacb4acf5c4466171ea577d7b8dc4d4 (diff)
powerpc: Fix accounting of softirq time when idle
commit cf9efce0ce31 (powerpc: Account time using timebase rather than PURR) used in_irq() to detect if the time was spent in interrupt processing. This only catches hardirq context so if we are in softirq context and in the idle loop we end up accounting it as idle time. If we instead use in_interrupt() we catch both softirq and hardirq time. The issue was found when running a network intensive workload. top showed the following: 0.0%us, 1.1%sy, 0.0%ni, 85.7%id, 0.0%wa, 9.9%hi, 3.3%si, 0.0%st 85.7% idle. But this was wildly different to the perf events data. To confirm the suspicion I ran something to keep the core busy: # yes > /dev/null & 8.2%us, 0.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 10.3%hi, 81.4%si, 0.0%st We only got 8.2% of the CPU for the userspace task and softirq has shot up to 81.4%. With the patch below top shows the correct stats: 0.0%us, 0.0%sy, 0.0%ni, 5.3%id, 0.0%wa, 13.3%hi, 81.3%si, 0.0%st Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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