Messages in this thread | | | From | "Huang\, Ying" <> | Subject | Re: [RFC 10/10] autonuma, memory tiering: Adjust hot threshold automatically | Date | Mon, 04 Nov 2019 18:12:50 +0800 |
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Peter Zijlstra <peterz@infradead.org> writes:
> On Mon, Nov 04, 2019 at 02:11:11PM +0800, Huang, Ying wrote: >> Peter Zijlstra <peterz@infradead.org> writes: >> >> > On Fri, Nov 01, 2019 at 03:57:27PM +0800, Huang, Ying wrote: >> > >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> >> index 0a83e9cf6685..22bdbb7afac2 100644 >> >> --- a/kernel/sched/fair.c >> >> +++ b/kernel/sched/fair.c >> >> @@ -1486,6 +1486,41 @@ static bool numa_migration_check_rate_limit(struct pglist_data *pgdat, >> >> return true; >> >> } >> >> >> >> +#define NUMA_MIGRATION_ADJUST_STEPS 16 >> >> + >> >> +static void numa_migration_adjust_threshold(struct pglist_data *pgdat, >> >> + unsigned long rate_limit, >> >> + unsigned long ref_threshold) >> >> +{ >> >> + unsigned long now = jiffies, last_threshold_jiffies; >> >> + unsigned long unit_threshold, threshold; >> >> + unsigned long try_migrate, ref_try_migrate, mdiff; >> >> + >> >> + last_threshold_jiffies = pgdat->autonuma_threshold_jiffies; >> >> + if (now > last_threshold_jiffies + >> >> + msecs_to_jiffies(sysctl_numa_balancing_scan_period_max) && >> >> + cmpxchg(&pgdat->autonuma_threshold_jiffies, >> >> + last_threshold_jiffies, now) == last_threshold_jiffies) { >> > >> > That is seriously unreadable gunk. >> >> The basic idea here is to adjust hot threshold every > > Oh, I figured out what it does, but it's just really hard to read > because of those silly variable names. > > This was just a first quick read through of the patches, and stuff like > this annoys me no end. I did start a rewrite with more sensible variable > names, but figured this might not be time for that.
Sorry about the poor naming. That is always hard for me.
> I still need to think and review the whole concept in more detail, now > that I've read the patches. But I need to chase regressions first :/
Thanks for your help!
> FWIW, can you post a SLIT / NUMA distance table for such a system?
Sure. Will send you as attachment in another email.
Best Regards, Huang, Ying
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