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From: Matthew Wilcox <willy@infradead.org>
To: WANG Rui <r@hev.cc>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Kees Cook <kees@kernel.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] binfmt_elf: Align eligible read-only PT_LOAD segments to PMD_SIZE for THP
Date: Mon, 2 Mar 2026 16:45:59 +0000	[thread overview]
Message-ID: <aaW-x-HVQpSuPRA1@casper.infradead.org> (raw)
In-Reply-To: <20260302155046.286650-1-r@hev.cc>

On Mon, Mar 02, 2026 at 11:50:46PM +0800, WANG Rui wrote:
> +config ELF_RO_LOAD_THP_ALIGNMENT
> +	bool "Align read-only ELF load segments for THP (EXPERIMENTAL)"
> +	depends on READ_ONLY_THP_FOR_FS

This doesn't deserve a config option.

> +#if defined(CONFIG_ELF_RO_LOAD_THP_ALIGNMENT) && PMD_SIZE <= SZ_32M

Why 32MB?  This is weird and not justified anywhere.

> +			if (hugepage_global_always() && !(cmds[i].p_flags & PF_W)
> +				&& IS_ALIGNED(cmds[i].p_vaddr | cmds[i].p_offset, PMD_SIZE)
> +				&& cmds[i].p_filesz >= PMD_SIZE && p_align < PMD_SIZE)
> +				p_align = PMD_SIZE;

Normal style is to put the '&&' at the end of the line:

			if (!(cmds[i].p_flags & PF_W) &&
			    IS_ALIGNED(cmds[i].p_vaddr | cmds[i].p_offset, PMD_SIZE) &&
			    cmds[i].p_filesz >= PMD_SIZE && p_align < PMD_SIZE))
				p_align = PMD_SIZE;

But this conditional is too complex to be at this level of indentation.
Factor it out into a helper:

			if (align_to_pmd(cmds) && p_align < PMD_SIZE)
				p_align = PMD_SIZE;



      reply	other threads:[~2026-03-02 16:46 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-02 15:50 WANG Rui
2026-03-02 16:45 ` Matthew Wilcox [this message]

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