Re: [PATCH] powerpc/smp: Dynamically build powerpc topology
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-09-04 22:10:29
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From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-09-04 22:10:29
Also in:
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On Wed, Aug 30, 2023 at 05:56:14PM +0530, Srikar Dronamraju wrote:
Currently there are four powerpc specific sched topologies. These are all statically defined. However not all these topologies are used by all powerpc systems. To avoid unnecessary degenerations by the scheduler , masks and flags are compared. However if the sched topologies are build dynamically then the code is simpler and there are greater chances of avoiding degenerations. Even x86 builds its sched topologies dynamically and new changes are very similar to the way x86 is building its topologies.
You're not stating it explicitly, but you're doing this as a performance optimization, right? The x86 thing didn't particularly care about avoiding degenerate topologies -- it's just that the fixed tables method grew unwieldy due to combinatorics. And how does this patch relate to the other series touching this? powerpc/smp: Shared processor sched optimizations