From: Peter Zijlstra <peterz@infradead.org>
To: "Gautham R. Shenoy" <gautham.shenoy@amd.com>
Cc: David Vernet <void@manifault.com>,
linux-kernel@vger.kernel.org, mingo@redhat.com,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
vschneid@redhat.com, kprateek.nayak@amd.com, aaron.lu@intel.com,
clm@meta.com, tj@kernel.org, roman.gushchin@linux.dev,
kernel-team@meta.com
Subject: Re: [PATCH v2 6/7] sched: Shard per-LLC shared runqueues
Date: Wed, 12 Jul 2023 14:22:52 +0200 [thread overview]
Message-ID: <20230712122252.GG3100107@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <ZK57IxhhZMw2ZaEA@BLR-5CG11610CF.amd.com>
On Wed, Jul 12, 2023 at 03:36:27PM +0530, Gautham R. Shenoy wrote:
> On some Intel servers, it is possible that the CPU numbers are
> interleaved across the two sockets. On my 2 socket, 32Cores per socket
> Ice Lake Server, all the even numbered CPUs are in one socket and all
> the odd numbered CPUs in the other socket.
>
> The SMT siblings are {0,64}, {2, 66}, .... on one socket and {1, 65},
> {3, 67}, .. on the other.
Yeah, Intel SMT enumeration is a mess. There's a random mix of {n,n+1}
and {0..n-1} {n..2n-1}. And then there's the fun hybrid stuff. Those
appear to do {n,n+1} for the big cores and then continue with the small
cores in a dense set. My 8+8 ADL, has:
{0,1} {2,3} {4,5} {6,7} {8,9} {10,11} {12,13} {14,15} {16} {17} {18} {19} {20} {21} {22} {23}
I suspect it might be easier to re-number the whole show at boot to fit
a sane pattern rather than trying to match the various random garbage
gifted to us by the BIOS.
I wouldn't worry about it too much at this point.
next prev parent reply other threads:[~2023-07-12 12:23 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 20:03 [PATCH v2 0/7] sched: Implement shared runqueue in CFS David Vernet
2023-07-10 20:03 ` [PATCH v2 1/7] sched: Expose move_queued_task() from core.c David Vernet
2023-07-10 20:03 ` [PATCH v2 2/7] sched: Move is_cpu_allowed() into sched.h David Vernet
2023-07-10 20:03 ` [PATCH v2 3/7] sched: Check cpu_active() earlier in newidle_balance() David Vernet
2023-07-10 20:03 ` [PATCH v2 4/7] sched/fair: Add SHARED_RUNQ sched feature and skeleton calls David Vernet
2023-07-11 9:45 ` Peter Zijlstra
2023-07-11 16:19 ` David Vernet
2023-07-12 8:39 ` Abel Wu
2023-07-12 21:34 ` David Vernet
2023-07-10 20:03 ` [PATCH v2 5/7] sched: Implement shared runqueue in CFS David Vernet
2023-07-11 10:18 ` Peter Zijlstra
2023-07-11 16:26 ` David Vernet
2023-07-12 6:00 ` Gautham R. Shenoy
2023-07-12 19:13 ` David Vernet
2023-07-12 10:47 ` Abel Wu
2023-07-12 22:16 ` David Vernet
2023-07-13 3:43 ` Abel Wu
2023-07-13 4:05 ` David Vernet
2023-07-13 7:58 ` Aaron Lu
2023-07-13 8:29 ` Peter Zijlstra
2023-07-10 20:03 ` [PATCH v2 6/7] sched: Shard per-LLC shared runqueues David Vernet
2023-07-11 10:49 ` Peter Zijlstra
2023-07-11 19:57 ` David Vernet
2023-07-12 10:06 ` Gautham R. Shenoy
2023-07-12 12:22 ` Peter Zijlstra [this message]
2023-07-10 20:03 ` [PATCH v2 7/7] sched: Move shared_runq to __{enqueue,dequeue}_entity() David Vernet
2023-07-11 10:51 ` Peter Zijlstra
2023-07-11 16:30 ` David Vernet
2023-07-11 11:42 ` [PATCH v2 0/7] sched: Implement shared runqueue in CFS Peter Zijlstra
2023-07-11 21:33 ` David Vernet
2023-07-21 9:12 ` Gautham R. Shenoy
2023-07-25 20:22 ` David Vernet
2023-08-02 6:32 ` Gautham R. Shenoy
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