Re: [patch 0/2] genirq, proc: Speedup /proc/stat interrupt statistics

From: Andrew Morton
Date: Wed Jan 30 2019 - 18:14:32 EST


On Wed, 30 Jan 2019 13:31:30 +0100 Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> Waiman reported that on large systems with a large amount of interrupts the
> readout of /proc/stat takes a long time to sum up the interrupt
> statistics. In principle this is not a problem. but for unknown reasons
> some enterprise quality software reads /proc/stat with a high frequency.
>
> The reason for this is that interrupt statistics are accounted per cpu. So
> the /proc/stat logic has to sum up the interrupt stats for each interrupt.
>
> The following series addresses this by making the interrupt statitics code
> in the core generate the sum directly and by making the loop in the
> /proc/stat read function smarter.
>

Has the speedup been quantified?