Re: [PATCH v2] x86/resctrl: Implement new mba_MBps throttling heuristic

From: Tony Luck
Date: Tue Jan 23 2024 - 19:29:59 EST


On Tue, Jan 23, 2024 at 05:07:50PM +0000, Luck, Tony wrote:
> >> I need to grab an SNC system to re-check that everything still works when re-based.
> >> But right now, this looks like adding the SNC series will be easy (famous last words!).
> >
> > Once you're ready - can you point me at something I can use as a stable branch to rebase onto?
>
> I'll be running the tests this afternoon. But I'm somewhat confident that they will pass.
>
> Tree is here: git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux.git branch "hopeful_snc"
>
> Commits are:
>
> 793635f10aeb x86/resctrl: Update documentation with Sub-NUMA cluster changes
> dca7ba785d6f x86/resctrl: Sub NUMA Cluster detection and enable
> e41bd88101c8 x86/resctrl: Introduce snc_nodes_per_l3_cache
> ccbab7875197 x86/resctrl: Add node-scope to the options for feature scope
> 2f0db8c7072b x86/resctrl: Split the rdt_domain and rdt_hw_domain structures
> 22697627cc5f x86/resctrl: Prepare for different scope for control/monitor operations
> f3ff831a9042 x86/resctrl: Prepare to split rdt_domain structure
> c0679868ee78 x86/resctrl: Prepare for new domain scope
> 327b4394f309 x86/resctrl: Implement new mba_MBps throttling heuristic
> 5b14817cf87e x86/resctrl: Read supported bandwidth sources using CPUID command
> 5699cd082e1f x86/resctrl: Remove hard-coded memory bandwidth limit
> 1b908debf53f x86/resctrl: Fix unused variable warning in cache_alloc_hsw_probe()
>
> Only the last of these (1b908debf53f) had been accepted by Boris into TIP x86/cache
> when I cut this tree yesterday.
>
> Two more applied by Boris today without any changes from what is in my tree, but the
> commit IDs in TIP are obviously different from in my tree.
>
> 54e35eb8611c x86/resctrl: Read supported bandwidth sources from CPUID
> 0976783bb123 x86/resctrl: Remove hard-coded memory bandwidth limit
>
> All the others have the normal risk that Boris will find some way to make them better.

All my SNC tests pass. So this tree is as good as I can make it.

Boris: After you take/reject "x86/resctrl: Implement new mba_MBps throttling heuristic"
in TIP x86/cache I will post v14 of the SNC series rebased to that TIP
branch.

-Tony