| Message ID | 20210308143146.3443166-1-dedekind1@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | intel_idle: update ICX C6 data | expand |
On Mon, Mar 8, 2021 at 3:31 PM Artem Bityutskiy <dedekind1@gmail.com> wrote: > > From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> > > This patch changes IceLake Xeon C6 latency from 128 us to 170 us. The latency > was measured with the "wult" tool and corresponds to the 99.99th percentile > when measuring with the "nic" method. Note, the 128 us figure correspond to the > median latency, but in intel_idle we use the "worst case" latency figure > instead. > > C6 target residency was increased from 384 us to 600 us, which may result in > less C6 residency in some workloads. This value was tested and compared to > values 384, and 1000. Value 600 is a reasonable tradeoff between power and > performance. > > Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> > Acked-by: Zhang Rui <rui.zhang@intel.com> > --- > drivers/idle/intel_idle.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Changelog: > v2->v3: Change target_residency from 1000us to 600us, based on Rui's feedback. > v1->v2: Re-measured ICX with newer BIOS 21D02, which has C1 demotion bug fixed. > > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > index 3273360f30f7..6cac0b748efa 100644 > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -744,8 +744,8 @@ static struct cpuidle_state icx_cstates[] __initdata = { > .name = "C6", > .desc = "MWAIT 0x20", > .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, > - .exit_latency = 128, > - .target_residency = 384, > + .exit_latency = 170, > + .target_residency = 600, > .enter = &intel_idle, > .enter_s2idle = intel_idle_s2idle, }, > { > -- Applied as 5.13 material, thanks!
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 3273360f30f7..6cac0b748efa 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -744,8 +744,8 @@ static struct cpuidle_state icx_cstates[] __initdata = { .name = "C6", .desc = "MWAIT 0x20", .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, - .exit_latency = 128, - .target_residency = 384, + .exit_latency = 170, + .target_residency = 600, .enter = &intel_idle, .enter_s2idle = intel_idle_s2idle, }, {