From: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
To: akpm@linux-foundation.org
Cc: andreyknvl@gmail.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, pasha.tatashin@soleen.com, surenb@google.com,
trintaeoitogc@gmail.com
Subject: Re: [PATCH] mm: alloc_tag: change the KASAN_TAG_WIDTH for HW_TAGS
Date: Mon, 28 Apr 2025 07:57:16 -0300 [thread overview]
Message-ID: <20250428105716.151167-1-trintaeoitogc@gmail.com> (raw)
In-Reply-To: <20250427172551.fbf81f14d4e6563c13007a65@linux-foundation.org>
Andrew Morton <akpm@linux-foundation.org> wrote:
> > the KASAN_TAG_WIDTH is 8 bits for both (HW_TAGS and SW_TAGS), but for
> > HW_TAGS the KASAN_TAG_WIDTH can be 4 bits bits because due to the design
> > of the MTE the memory words for storing metadata only need 4 bits.
> > Change the preprocessor define KASAN_TAG_WIDTH for check if SW_TAGS is
> > define, so KASAN_TAG_WIDTH should be 8 bits, but if HW_TAGS is define,
> > so KASAN_TAG_WIDTH should be 4 bits.
>
> Why?
>
> I assume the effect is to save a few flags bits under some
> circumstances? But that's just me guessing - please fully describe the
> motivation and effects within changelogs.
Ok, I will change the commit message with the "why", and send a v2.
Thanks.
prev parent reply other threads:[~2025-04-28 10:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-26 18:08 Guilherme Giacomo Simoes
2025-04-28 0:25 ` Andrew Morton
2025-04-28 10:57 ` Guilherme Giacomo Simoes [this message]
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