From: Ankur Arora <ankur.a.arora@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
david@redhat.com, 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,
raghavendra.kt@amd.com, boris.ostrovsky@oracle.com,
konrad.wilk@oracle.com
Subject: Re: [PATCH v5 12/14] mm: add config option for clearing page-extents
Date: Thu, 10 Jul 2025 09:31:50 -0700 [thread overview]
Message-ID: <87ldowovm1.fsf@oracle.com> (raw)
In-Reply-To: <20250710005835.8819c30579e37b90d79f4c53@linux-foundation.org>
Andrew Morton <akpm@linux-foundation.org> writes:
> On Wed, 9 Jul 2025 17:59:24 -0700 Ankur Arora <ankur.a.arora@oracle.com> wrote:
>
>> This is only available with !CONFIG_HIGHMEM because the intent is to
>> use architecture support to clear contiguous extents in a single
>> operation (ex. via FEAT_MOPS on arm64, string instructions on x86)
>> which excludes any possibility of interspersing kmap()/kunmap().
>
> I'm feeling dumb. What does the use of a string instruction have to do
> with kmap/kunmap?
Sorry, that might have been unnecessarily inscrutable. How about
something like this:
This is only enabled with !CONFIG_HIGHMEM because the intent is
to use architecture support to clear contiguous extents in a
single interruptible operation (ex. via FEAT_MOPS on arm64,
string instructions on x86).
Given that we might be zeroing the whole extent with a single
instruction, this excludes any possibility of constructing
intermediate HIGHMEM maps.
--
ankur
next prev parent reply other threads:[~2025-07-10 16:32 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-10 0:59 [PATCH v5 00/14] mm: folio_zero_user: clearing of page-extents Ankur Arora
2025-07-10 0:59 ` [PATCH v5 01/14] perf bench mem: Remove repetition around time measurement Ankur Arora
2025-07-15 20:04 ` Namhyung Kim
2025-07-10 0:59 ` [PATCH v5 02/14] perf bench mem: Defer type munging of size to float Ankur Arora
2025-07-15 20:05 ` Namhyung Kim
2025-07-16 2:17 ` Ankur Arora
2025-07-10 0:59 ` [PATCH v5 03/14] perf bench mem: Move mem op parameters into a structure Ankur Arora
2025-07-15 20:06 ` Namhyung Kim
2025-07-10 0:59 ` [PATCH v5 04/14] perf bench mem: Pull out init/fini logic Ankur Arora
2025-07-15 20:09 ` Namhyung Kim
2025-07-10 0:59 ` [PATCH v5 05/14] perf bench mem: Switch from zalloc() to mmap() Ankur Arora
2025-07-15 20:09 ` Namhyung Kim
2025-07-10 0:59 ` [PATCH v5 06/14] perf bench mem: Allow mapping of hugepages Ankur Arora
2025-07-15 20:12 ` Namhyung Kim
2025-07-16 2:32 ` Ankur Arora
2025-07-10 0:59 ` [PATCH v5 07/14] perf bench mem: Allow chunking on a memory region Ankur Arora
2025-07-15 20:17 ` Namhyung Kim
2025-07-16 2:34 ` Ankur Arora
2025-07-10 0:59 ` [PATCH v5 08/14] perf bench mem: Refactor mem_options Ankur Arora
2025-07-15 20:18 ` Namhyung Kim
2025-07-10 0:59 ` [PATCH v5 09/14] perf bench mem: Add mmap() workloads Ankur Arora
2025-07-15 20:20 ` Namhyung Kim
2025-07-16 2:40 ` Ankur Arora
2025-07-10 0:59 ` [PATCH v5 10/14] x86/mm: Simplify clear_page_* Ankur Arora
2025-07-11 11:47 ` David Hildenbrand
2025-07-11 17:26 ` Ankur Arora
2025-07-11 19:03 ` David Hildenbrand
2025-07-11 19:24 ` Ankur Arora
2025-07-11 19:27 ` David Hildenbrand
2025-07-10 0:59 ` [PATCH v5 11/14] x86/clear_page: Introduce clear_pages() Ankur Arora
2025-07-10 0:59 ` [PATCH v5 12/14] mm: add config option for clearing page-extents Ankur Arora
2025-07-10 7:58 ` Andrew Morton
2025-07-10 16:31 ` Ankur Arora [this message]
2025-07-11 11:39 ` David Hildenbrand
2025-07-11 17:25 ` Ankur Arora
2025-07-11 19:14 ` David Hildenbrand
2025-07-11 19:35 ` Ankur Arora
2025-07-11 11:40 ` David Hildenbrand
2025-07-11 17:32 ` Ankur Arora
2025-07-11 19:26 ` David Hildenbrand
2025-07-11 19:42 ` Ankur Arora
2025-07-14 20:35 ` Ankur Arora
2025-07-15 20:59 ` David Hildenbrand
2025-07-10 0:59 ` [PATCH v5 13/14] mm: memory: support " Ankur Arora
2025-07-11 11:44 ` David Hildenbrand
2025-07-11 13:27 ` Raghavendra K T
2025-07-11 17:39 ` Ankur Arora
2025-07-15 22:08 ` David Hildenbrand
2025-07-16 3:19 ` Ankur Arora
2025-07-16 8:03 ` David Hildenbrand
2025-07-16 17:54 ` Ankur Arora
2025-07-10 0:59 ` [PATCH v5 14/14] x86/clear_pages: Support clearing of page-extents Ankur Arora
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