linux-kernel - Re: [PATCH 0/8] Introduce a huge-page pre-zeroing mechanism

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Message-Id: <20251229122856.7397-1-lizhe.67@bytedance.com>
Date: Mon, 29 Dec 2025 20:28:56 +0800
From: "Li Zhe" <lizhe.67@...edance.com>
To: <fvdl@...gle.com>
Cc: <akpm@...ux-foundation.org>, <david@...nel.org>, 
	<linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>, 
	<lizhe.67@...edance.com>, <muchun.song@...ux.dev>, <osalvador@...e.de>
Subject: Re: [PATCH 0/8] Introduce a huge-page pre-zeroing mechanism

On Fri, 26 Dec 2025 13:42:13 -0800, fvdl@...gle.com wrote:

> Is there any situation where you would write anything else than 'max'
> to the new sysfs file? E.g. in which scenarios does it make sense to
> *not* pre-zero all freed hugetlb folios? There doesn't seem to be a
> point to just doing a certain number. You can't know for sure if the
> number you read will remain correct, as it's just a snapshot. So how
> would you determine a correct number other than 'max'?

My view is that each application knows its own huge-page requirement
and should therefore write the corresponding number into the
"zeroable_hugepages" interface. Since the zeroing work is accounted
to the application process, the CPU time it consumes can be
constrained through that process's cgroup.

Thanks,
Zhe