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From: "Summers, Stuart" <stuart.summers@intel.com>
To: "Brost, Matthew" <matthew.brost@intel.com>,
	"Simon.Richter@hogyros.de" <Simon.Richter@hogyros.de>
Cc: "intel-xe@lists.freedesktop.org" <intel-xe@lists.freedesktop.org>,
	"Auld,  Matthew" <matthew.auld@intel.com>
Subject: Re: [PATCH v5 2/2] drm/xe: Enable 2M pages in xe_migrate_vram
Date: Tue, 14 Oct 2025 03:08:42 +0000	[thread overview]
Message-ID: <7c4585ccd8b175c764917b0a9de511744bddd35f.camel@intel.com> (raw)
In-Reply-To: <7b89fed3-3b8f-4787-8ef4-17f24477d829@hogyros.de>

On Tue, 2025-10-14 at 11:17 +0900, Simon Richter wrote:
> Hi,
> 
> On 10/14/25 2:22 AM, Summers, Stuart wrote:
> 
> > So according to
> > https://docs.kernel.org/admin-guide/mm/hugetlbpage.html
> > we can potentially get 4M-256M pages on some architectures.
> 
> These exist but will not be the finest granularity on those 
> architectures, so these should never appear as PAGE_SIZE.
> 
> The kernel is unable to load executables that have a smaller
> alignment 
> than PAGE_SIZE for their loadable segments, so that gives a nice
> upper 
> bound for what we need to expect.
> 
> There might be places that make the assumption that if there is a 
> hugetlb size that the host supports, it will be 2M, but the worst
> thing 
> that can happen there is a fallback to PAGE_SIZE and slightly
> degraded 
> performance.

Yeah makes sense Simon and thanks for the follow-up!

-Stuart

> 
>     Simon


  reply	other threads:[~2025-10-14  3:08 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-13  3:45 [PATCH v5 0/2] Different page size handle in migrate layer Matthew Brost
2025-10-13  3:45 ` [PATCH v5 1/2] drm/xe: Fix build_pt_update_batch_sram for non-4K PAGE_SIZE Matthew Brost
2025-10-13 16:38   ` [v5,1/2] " Simon Richter
2025-10-13 16:53   ` [PATCH v5 1/2] " Summers, Stuart
2025-10-13  3:45 ` [PATCH v5 2/2] drm/xe: Enable 2M pages in xe_migrate_vram Matthew Brost
2025-10-13 17:08   ` Summers, Stuart
2025-10-13 17:14     ` Matthew Brost
2025-10-13 17:22       ` Summers, Stuart
2025-10-13 17:34         ` Matthew Brost
2025-10-13 18:01           ` Summers, Stuart
2025-10-14  2:17         ` Simon Richter
2025-10-14  3:08           ` Summers, Stuart [this message]
2025-10-13 17:29       ` Simon.Richter
2025-10-13 17:32         ` Matthew Brost
2025-10-13  5:38 ` ✓ CI.KUnit: success for Different page size handle in migrate layer (rev2) Patchwork
2025-10-13  6:23 ` ✓ Xe.CI.BAT: " Patchwork
2025-10-13  6:51 ` ✓ Xe.CI.Full: " Patchwork

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