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From: Dave Hansen <dave.hansen@intel.com>
To: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Cc: hpa@zytor.com, hch@infradead.org,
	nick.desaulniers+lkml@gmail.com, kuan-ying.lee@canonical.com,
	masahiroy@kernel.org, samuel.holland@sifive.com,
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Subject: Re: [PATCH v3 09/14] x86: Minimal SLAB alignment
Date: Wed, 9 Apr 2025 08:24:11 -0700	[thread overview]
Message-ID: <0770a3d4-c8ff-4172-9eda-c9debfee6d03@intel.com> (raw)
In-Reply-To: <czzcsmwaf42v47arvmwgrh4p7h3misoarremtc7r2cme2ceuud@yya5jfuqhuye>

On 4/9/25 05:49, Maciej Wieczor-Retman wrote:
> The differences looked mostly like noise, sometimes the higher alignment would
> use up a little bit less memory, sometimes a little bit more. I looked at all
> values in "cat /proc/meminfo".
> 
> Is there some slab/slub benchmark for the kernel that would make sense to
> checkout here?

You don't need to benchmark anything. Just mention that it will waste
memory and also give *some* ballpark estimate on how much. Just looking
at your laptop's /proc/slabinfo would be a good start.

Oh, and it wouldn't hurt to find out when and why the minimal slab
alignment got dropped down to 8 bytes. I _thought_ it was higher at some
point. Presumably there was a good reason for it and you're now undoing
part of it.


  reply	other threads:[~2025-04-09 15:24 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-04 13:14 [PATCH v3 00/14] kasan: x86: arm64: KASAN tag-based mode for x86 Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 01/14] kasan: sw_tags: Use arithmetic shift for shadow computation Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 02/14] kasan: sw_tags: Support tag widths less than 8 bits Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 03/14] x86: Add arch specific kasan functions Maciej Wieczor-Retman
2025-04-04 16:06   ` Dave Hansen
2025-04-09  7:16     ` Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 04/14] kasan: arm64: x86: Make special tags arch specific Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 05/14] x86: Reset tag for virtual to physical address conversions Maciej Wieczor-Retman
2025-04-04 16:42   ` Dave Hansen
2025-04-09  7:36     ` Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 06/14] x86: Physical address comparisons in fill_p*d/pte Maciej Wieczor-Retman
2025-04-04 16:56   ` Dave Hansen
2025-04-09  7:49     ` Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 07/14] x86: KASAN raw shadow memory PTE init Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 08/14] x86: LAM initialization Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 09/14] x86: Minimal SLAB alignment Maciej Wieczor-Retman
2025-04-04 16:59   ` Dave Hansen
2025-04-09 12:49     ` Maciej Wieczor-Retman
2025-04-09 15:24       ` Dave Hansen [this message]
2025-04-04 13:14 ` [PATCH v3 10/14] x86: Update the KASAN non-canonical hook Maciej Wieczor-Retman
2025-04-04 17:37   ` Dave Hansen
2025-04-09 14:34     ` Maciej Wieczor-Retman
2025-04-09 18:29       ` Dave Hansen
2025-04-04 13:14 ` [PATCH v3 11/14] x86: Handle int3 for inline KASAN reports Maciej Wieczor-Retman
2025-04-04 17:55   ` Dave Hansen
2025-04-09 14:48     ` Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 12/14] kasan: Fix inline mode for x86 tag-based mode Maciej Wieczor-Retman
2025-04-04 13:14 ` [PATCH v3 13/14] mm: Unpoison pcpu chunks with base address tag Maciej Wieczor-Retman
2025-04-04 18:08   ` Dave Hansen
2025-04-09 16:32     ` Maciej Wieczor-Retman
2025-04-09 17:12       ` Dave Hansen
2025-04-04 13:14 ` [PATCH v3 14/14] x86: Make software tag-based kasan available Maciej Wieczor-Retman

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