From: Hanna L. <ha...@us...> - 2002-07-23 21:20:48
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Some things people have posted to the list in the past two weeks we could talk about are: Erich Focht's new NUMA scheduler http://marc.theaimsgroup.com/?l=lse-tech&m=102734685425321&w=2 Randy Hron's cpu affinity results http://marc.theaimsgroup.com/?l=lse-tech&m=102694590707833&w=2 Adam Litke's lockmeter port to 2.5.25|26 http://marc.theaimsgroup.com/?l=lse-tech&m=102702771127281&w=2 Anything else? Hanna |
From: Andrea A. <an...@su...> - 2002-07-23 23:32:41
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On Tue, Jul 23, 2002 at 02:24:33PM -0700, Hanna Linder wrote: > Randy Hron's cpu affinity results > > http://marc.theaimsgroup.com/?l=lse-tech&m=102694590707833&w=2 I thought about this for a while and I think I solved it in 2.4.19rc3aa1 (completely untested but I can bet): http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.19rc3aa1/00_net-softirq-1 BTW, could somebody re-run the benchmarks that expectedly shows the bad regression of the original irq-balance patch and compare it with my new irq-balance algorithm that I partly rewrote while merging it in my tree? As far I could see (before ever hearing about any benchmark) the previous irqbalance was mainly a beauty-hack to make P4 smp look like a PIII smp in /proc/interrupts, some of the very obvious bugs: the uninitialized idle_timestamp, the unconditional overwriting of the ioapic settings even if the routing decision didn't change, the overkill frequency of the rounting change, the icache trashing due superflous routing migrations. http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.19rc3aa1/30_irq-balance-12 thanks, Andrea |
From: Anton B. <an...@sa...> - 2002-07-24 08:28:25
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> BTW, could somebody re-run the benchmarks that expectedly shows the bad > regression of the original irq-balance patch and compare it with my new > irq-balance algorithm that I partly rewrote while merging it in my > tree? As far I could see (before ever hearing about any benchmark) the > previous irqbalance was mainly a beauty-hack to make P4 smp look like a > PIII smp in /proc/interrupts, some of the very obvious bugs: the > uninitialized idle_timestamp, the unconditional overwriting of the > ioapic settings even if the routing decision didn't change, the overkill > frequency of the rounting change, the icache trashing due superflous > routing migrations. The unconditional overwriting and high frequency of updates were the two things I found when porting this to ppc64. Its especially bad now that HZ = 1000, it should not be doing an update every time jiffies changes. Anton |
From: Andrea A. <an...@su...> - 2002-07-24 12:40:16
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On Wed, Jul 24, 2002 at 08:25:25AM +1000, Anton Blanchard wrote: > > > BTW, could somebody re-run the benchmarks that expectedly shows the bad > > regression of the original irq-balance patch and compare it with my new > > irq-balance algorithm that I partly rewrote while merging it in my > > tree? As far I could see (before ever hearing about any benchmark) the > > previous irqbalance was mainly a beauty-hack to make P4 smp look like a > > PIII smp in /proc/interrupts, some of the very obvious bugs: the > > uninitialized idle_timestamp, the unconditional overwriting of the > > ioapic settings even if the routing decision didn't change, the overkill > > frequency of the rounting change, the icache trashing due superflous > > routing migrations. > > The unconditional overwriting and high frequency of updates were the two > things I found when porting this to ppc64. Its especially bad now that > HZ = 1000, it should not be doing an update every time jiffies changes. of course while fixing it I also made the update correctly in function of HZ, so it doesn't matter what HZ it is. But really the only problems weren't the frequent updates and unconditional overwriting, the thing keeps bouncing if it doesn't find any better routing and it has the other issues mentioned above, all should be fixed in my rewrote version in -aa. Andrea |
From: Andrew T. <hab...@us...> - 2002-07-24 21:11:07
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On Tuesday 23 July 2002 6:33 pm, Andrea Arcangeli wrote: > On Tue, Jul 23, 2002 at 02:24:33PM -0700, Hanna Linder wrote: > > Randy Hron's cpu affinity results > > > > =09http://marc.theaimsgroup.com/?l=3Dlse-tech&m=3D102694590707833&w=3D= 2 > > I thought about this for a while and I think I solved it in 2.4.19rc3aa= 1 > (completely untested but I can bet): > > =09http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4= /2.4.1 >9rc3aa1/00_net-softirq-1 > > BTW, could somebody re-run the benchmarks that expectedly shows the bad > regression of the original irq-balance patch and compare it with my new > irq-balance algorithm that I partly rewrote while merging it in my > tree? As far I could see (before ever hearing about any benchmark) the > previous irqbalance was mainly a beauty-hack to make P4 smp look like a > PIII smp in /proc/interrupts, some of the very obvious bugs: the > uninitialized idle_timestamp, the unconditional overwriting of the > ioapic settings even if the routing decision didn't change, the overkil= l > frequency of the rounting change, the icache trashing due superflous > routing migrations. Yes, I wil l run this on Netbench. FYI, I just did this on 2.5.25 with=20 irqbalance enabled/disabled and it was a 10% difference. =20 -Andrew |