From: Francois Dugast <francois.dugast@intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Matthew Brost" <matthew.brost@intel.com>,
iommu@lists.linux.dev, intel-xe@lists.freedesktop.org,
"Joerg Roedel" <joerg.roedel@amd.com>,
"Calvin Owens" <calvin@wbinvd.org>,
"David Woodhouse" <dwmw2@infradead.org>,
"Will Deacon" <will@kernel.org>,
"Robin Murphy" <robin.murphy@arm.com>,
"Samiullah Khawaja" <skhawaja@google.com>,
"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
"Tina Zhang" <tina.zhang@intel.com>,
"Lu Baolu" <baolu.lu@linux.intel.com>,
"Kevin Tian" <kevin.tian@intel.com>
Subject: Re: Xe performance regression with recent IOMMU changes
Date: Fri, 23 Jan 2026 17:27:24 +0100 [thread overview]
Message-ID: <aXOhbK6Ed9WPbz0u@fdugast-desk> (raw)
In-Reply-To: <20260122133131.GL1134360@nvidia.com>
On Thu, Jan 22, 2026 at 09:31:31AM -0400, Jason Gunthorpe wrote:
> Try the patches, give me the new numbers,
Thanks for the suggestion but they do not seem to help, see new
execution times below in ns, collected this time without kprobe
to reduce variation:
# iommu-tip + https://patch.msgid.link/r/0-v2-973a6bdc820f+693-iommpt_map_direct_jgg@nvidia.com
+-----------------------------------+--------+--------+--------+
| | 4KB | 64KB | 2MB |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_map_pages() | 660 | 3951 | 113813 |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_unmap_pages() | 610 | 11136 | 322802 |
+-----------------------------------+--------+--------+--------+
# drm-tip
+-----------------------------------+--------+--------+--------+
| | 4KB | 64KB | 2MB |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_map_pages() | 687 | 3890 | 114749 |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_unmap_pages() | 621 | 11180 | 334472 |
+-----------------------------------+--------+--------+--------+
# drm-tip + revert of IOMMU changes
+-----------------------------------+--------+--------+--------+
| | 4KB | 64KB | 2MB |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_map_pages() | 355 | 3545 | 102706 |
+-----------------------------------+--------+--------+--------+
| drm_pagemap_migrate_unmap_pages() | 305 | 4341 | 125919 |
+-----------------------------------+--------+--------+--------+
> tell me if you have the non-cache iommu
The setup used in this test has non-cache coherent IOMMU.
> and I will give you another one to try.
Sure, please do.
Francois
next prev parent reply other threads:[~2026-01-23 16:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 13:02 Xe performance regression with recent IOMMU changes Francois Dugast
2026-01-21 13:11 ` Jason Gunthorpe
2026-01-21 18:04 ` Jason Gunthorpe
2026-01-22 6:15 ` Matthew Brost
2026-01-22 7:29 ` Leon Romanovsky
2026-01-22 7:36 ` Matthew Brost
2026-01-22 10:26 ` Leon Romanovsky
2026-01-22 13:31 ` Jason Gunthorpe
2026-01-23 16:27 ` Francois Dugast [this message]
2026-01-23 19:07 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aXOhbK6Ed9WPbz0u@fdugast-desk \
--to=francois.dugast@intel.com \
--cc=baolu.lu@linux.intel.com \
--cc=calvin@wbinvd.org \
--cc=dwmw2@infradead.org \
--cc=intel-xe@lists.freedesktop.org \
--cc=iommu@lists.linux.dev \
--cc=jgg@nvidia.com \
--cc=joerg.roedel@amd.com \
--cc=kevin.tian@intel.com \
--cc=matthew.brost@intel.com \
--cc=robin.murphy@arm.com \
--cc=skhawaja@google.com \
--cc=thomas.hellstrom@linux.intel.com \
--cc=tina.zhang@intel.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox