Messages in this thread | | | Date | Mon, 18 May 2020 21:39:30 -0400 | From | Daniel Jordan <> | Subject | Re: [PATCH] swap: Add percpu cluster_next to reduce lock contention on swap cache |
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On Mon, May 18, 2020 at 02:37:15PM +0800, Huang, Ying wrote: > Daniel Jordan <daniel.m.jordan@oracle.com> writes: > > On Thu, May 14, 2020 at 03:04:24PM +0800, Huang Ying wrote: > >> And the pmbench score increases 15.9%. > > > > What metric is that, and how long did you run the benchmark for? > > I run the benchmark for 1800s. The metric comes from the following > output of the pmbench, > > [1] Benchmark done - took 1800.088 sec for 122910000 page access > > That is, the throughput is 122910000 / 1800.088 = 68280.0 (accesses/s). > Then we sum the values from the different processes.
Ok.
> > It's just a nit but SWP_SOLIDSTATE and 'if (si->cluster_info)' are two ways to > > check the same thing and I'd stick with the one that's already there. > > Yes. In effect, (si->flags & SWP_SOLIDSTATE) and (si->cluster_info) > always has same value at least for now. But I don't think they are > exactly same in semantics. So I would rather to use their exact > semantics.
Oh, but I thought the swap clusters were for scaling the locking for fast devices, so that both checks have the same semantics now, and presumably would in the future.
It's a minor point, I'm fine either way.
> The first swap slot is the swap partition header, you cand find the > corresponding code in syscall swapon function, below comments "Read the
Aha, thanks.
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