From: Ankur Arora <ankur.a.arora@oracle.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Ankur Arora <ankur.a.arora@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
akpm@linux-foundation.org, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com,
mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org,
acme@kernel.org, namhyung@kernel.org, tglx@linutronix.de,
willy@infradead.org, jon.grimm@amd.com, bharata@amd.com,
raghavendra.kt@amd.com, boris.ostrovsky@oracle.com,
konrad.wilk@oracle.com
Subject: Re: [PATCH v4 00/13] x86/mm: Add multi-page clearing
Date: Mon, 16 Jun 2025 11:25:28 -0700 [thread overview]
Message-ID: <87o6uny25j.fsf@oracle.com> (raw)
In-Reply-To: <5d3e4538-9757-4d6e-bed1-900c9859d860@intel.com>
Dave Hansen <dave.hansen@intel.com> writes:
> On 6/15/25 22:22, Ankur Arora wrote:
>> This series adds multi-page clearing for hugepages, improving on the
>> current page-at-a-time approach in two ways:
>>
>> - amortizes the per-page setup cost over a larger extent
>> - when using string instructions, exposes the real region size to the
>> processor. A processor could use that as a hint to optimize based
>> on the full extent size. AMD Zen uarchs, as an example, elide
>> allocation of cachelines for regions larger than L3-size.
>
> Have you happened to do any testing outside of 'perf bench'?
Yeah. My original tests were with qemu creating a pinned guest (where it
would go and touch pages after allocation.)
I think perf bench is a reasonably good test is because a lot of demand
faulting often just boils down to the same kind of loop. And of course
MAP_POPULATE is essentially equal to the clearing loop in the kernel.
I'm happy to try other tests if you have some in mind.
And, thanks for the quick comments!
--
ankur
next prev parent reply other threads:[~2025-06-16 18:25 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-16 5:22 [PATCH v4 00/13] x86/mm: Add multi-page clearing Ankur Arora
2025-06-16 5:22 ` [PATCH v4 01/13] perf bench mem: Remove repetition around time measurement Ankur Arora
2025-06-16 5:22 ` [PATCH v4 02/13] perf bench mem: Defer type munging of size to float Ankur Arora
2025-06-16 5:22 ` [PATCH v4 03/13] perf bench mem: Move mem op parameters into a structure Ankur Arora
2025-06-16 5:22 ` [PATCH v4 04/13] perf bench mem: Pull out init/fini logic Ankur Arora
2025-06-16 5:22 ` [PATCH v4 05/13] perf bench mem: Switch from zalloc() to mmap() Ankur Arora
2025-06-16 5:22 ` [PATCH v4 06/13] perf bench mem: Allow mapping of hugepages Ankur Arora
2025-06-16 5:22 ` [PATCH v4 07/13] perf bench mem: Allow chunking on a memory region Ankur Arora
2025-06-16 5:22 ` [PATCH v4 08/13] perf bench mem: Refactor mem_options Ankur Arora
2025-06-16 5:22 ` [PATCH v4 09/13] perf bench mem: Add mmap() workloads Ankur Arora
2025-06-16 5:22 ` [PATCH v4 10/13] x86/mm: Simplify clear_page_* Ankur Arora
2025-06-16 14:35 ` Dave Hansen
2025-06-16 14:38 ` Peter Zijlstra
2025-06-16 18:18 ` Ankur Arora
2025-06-16 16:48 ` kernel test robot
2025-06-16 5:22 ` [PATCH v4 11/13] x86/clear_page: Introduce clear_pages() Ankur Arora
2025-06-16 5:22 ` [PATCH v4 12/13] mm: memory: allow arch override for folio_zero_user() Ankur Arora
2025-06-16 5:22 ` [PATCH v4 13/13] x86/folio_zero_user: Add multi-page clearing Ankur Arora
2025-06-16 11:39 ` kernel test robot
2025-06-16 14:44 ` Dave Hansen
2025-06-16 14:50 ` Peter Zijlstra
2025-06-16 15:03 ` Dave Hansen
2025-06-16 18:20 ` Ankur Arora
2025-06-16 14:58 ` Matthew Wilcox
2025-06-16 18:47 ` Ankur Arora
2025-06-19 23:51 ` Ankur Arora
2025-06-16 15:06 ` [PATCH v4 00/13] x86/mm: " Dave Hansen
2025-06-16 18:25 ` Ankur Arora [this message]
2025-06-16 18:30 ` Dave Hansen
2025-06-16 18:43 ` Ankur Arora
2025-07-04 8:15 ` Raghavendra K T
2025-07-07 21:02 ` Ankur Arora
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