linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Yicong Yang <yangyicong@huawei.com>
Cc: <catalin.marinas@arm.com>, <will@kernel.org>,
	<mark.rutland@arm.com>, <linux-arm-kernel@lists.infradead.org>,
	<oliver.upton@linux.dev>, <broonie@kernel.org>,
	<ryan.roberts@arm.com>, <linuxarm@huawei.com>,
	<jonathan.cameron@huawei.com>,
	<shameerali.kolothum.thodi@huawei.com>,
	<prime.zeng@hisilicon.com>, <xuwei5@huawei.com>,
	<wangkefeng.wang@huawei.com>, <yangyicong@hisilicon.com>
Subject: Re: [PATCH 0/2] Support Armv8.9/v9.4 FEAT_HAFT
Date: Fri, 02 Aug 2024 11:40:16 +0100	[thread overview]
Message-ID: <86cymr1a3z.wl-maz@kernel.org> (raw)
In-Reply-To: <20240802093458.32683-1-yangyicong@huawei.com>

On Fri, 02 Aug 2024 10:34:56 +0100,
Yicong Yang <yangyicong@huawei.com> wrote:
> 
> From: Yicong Yang <yangyicong@hisilicon.com>
> 
> This series adds basic support for FEAT_HAFT introduced in Armv8.9/v9.4
> and enable ARCH_HAS_NONLEAF_PMD_YOUNG. The latter will be used in
> lru-gen aging. Tested with lru-gen in below steps:
> 1. Generate a 1GiB workingset by `stress-ng --vm 1`. Then hang the task to
>    stop accessing the memory. (AF bit won't be updated)
> 2. try to age the memory by /sys/kernel/debug/lru_gen
> 
> Run above steps with LRU_GEN_NONLEAF_YOUNG(0x4) and not respectively
> (switching by /sys/kernel/mm/lru_gen/enabled). LRU_GEN_NONLEAF_YOUNG
> will clear and test the PMD AF bit on page walking for aging,
> otherwise will clear and test the PTE AF bit for aging. In this case
> LRU_GEN_NONLEAF_YOUNG will improve the efficiency of page scanning
> since pages won't be accessed and we don't need to scan each PTE.

Improve by how much? Can you please publish numbers that demonstrate
the effect of this feature?

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.


  parent reply	other threads:[~2024-08-02 10:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-02  9:34 [PATCH 0/2] Support Armv8.9/v9.4 FEAT_HAFT Yicong Yang
2024-08-02  9:34 ` [PATCH 1/2] arm64: Add support for FEAT_HAFT Yicong Yang
2024-08-02 10:37   ` Marc Zyngier
2024-08-06  3:09     ` Yicong Yang
2024-08-06  7:57       ` Marc Zyngier
2024-08-06 13:11         ` Yicong Yang
2024-08-02  9:34 ` [PATCH 2/2] arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG Yicong Yang
2024-08-02 10:40 ` Marc Zyngier [this message]
2024-08-06  3:43   ` [PATCH 0/2] Support Armv8.9/v9.4 FEAT_HAFT Yicong Yang
2024-08-06  8:06     ` Marc Zyngier
2024-08-06 13:35       ` Yicong Yang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=86cymr1a3z.wl-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=jonathan.cameron@huawei.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linuxarm@huawei.com \
    --cc=mark.rutland@arm.com \
    --cc=oliver.upton@linux.dev \
    --cc=prime.zeng@hisilicon.com \
    --cc=ryan.roberts@arm.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=wangkefeng.wang@huawei.com \
    --cc=will@kernel.org \
    --cc=xuwei5@huawei.com \
    --cc=yangyicong@hisilicon.com \
    --cc=yangyicong@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).