Bug 2269883

Summary:	CONFIG_READ_ONLY_THP_FOR_FS is unset
Product:	[Fedora] Fedora	Reporter:	Avi Kivity <avi.kivity>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	38	CC:	acaringi, adscvr, airlied, alciregi, bskeggs, hdegoede, hpa, jarod, josef, kernel-maint, linville, masami256, mchehab, ptalbert, steved
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	kernel-6.8.4-300.fc40 kernel-6.8.4-200.fc39 kernel-6.8.4-100.fc38	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2024-04-05 23:10:19 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Avi Kivity 2024-03-16 20:10:10 UTC

1. Please describe the problem:

CONFIG_READ_ONLY_THP_FOR_FS allows madvise(MADV_HUGEPAGE) to apply to file-backed memory. It's specifically useful for backing large instruction footprint binaries with hugepages, improving performance. However, it's unset.

The features was marked experimental in 2019, but 5 years have passes.

2. What is the Version-Release number of the kernel:

6.7.9-100.fc38.x86_64

3. Did it work previously in Fedora? If so, what kernel version did the issue
*first* appear? Old kernels are available for download at

This is not a regression.

4. Can you reproduce this issue? If so, please provide the steps to reproduce
the issue below:

$ grep READ_ONLY_THP_FOR_FS /boot/config*
/boot/config-6.7.6-100.fc38.x86_64:# CONFIG_READ_ONLY_THP_FOR_FS is not set
/boot/config-6.7.7-100.fc38.x86_64:# CONFIG_READ_ONLY_THP_FOR_FS is not set
/boot/config-6.7.9-100.fc38.x86_64:# CONFIG_READ_ONLY_THP_FOR_FS is not set

5. Does this problem occur with the latest Rawhide kernel? To install the
Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by
``sudo dnf update --enablerepo=rawhide kernel``:

I checked the sources, and yes.

6. Are you running any modules that not shipped with directly Fedora's kernel?:

Nope

7. Please attach the kernel logs. You can get the complete kernel log
for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the
issue occurred on a previous boot, use the journalctl ``-b`` flag.

I believe logs are unnecessary for this report.

I'd file a patch myself, but got lost where this is defined, since each repo references another.

Reproducible: Always

Comment 1 Avi Kivity 2024-03-16 20:11:00 UTC

Note, since transparent hugepages default to [madvise], this cannot cause a regression.

Comment 2 Fedora Update System 2024-04-04 02:12:56 UTC

FEDORA-2024-7dd4b3b9a4 (kernel-6.8.3-200.fc39 and kernel-headers-6.8.3-200.fc39) has been submitted as an update to Fedora 39.
https://bodhi.fedoraproject.org/updates/FEDORA-2024-7dd4b3b9a4

Comment 3 Fedora Update System 2024-04-04 02:12:59 UTC

FEDORA-2024-41295cb23c (kernel-6.8.3-100.fc38 and kernel-headers-6.8.3-100.fc38) has been submitted as an update to Fedora 38.
https://bodhi.fedoraproject.org/updates/FEDORA-2024-41295cb23c

Comment 4 Fedora Update System 2024-04-04 02:13:02 UTC

FEDORA-2024-6b7d840efe (kernel-6.8.3-300.fc40 and kernel-headers-6.8.3-300.fc40) has been submitted as an update to Fedora 40.
https://bodhi.fedoraproject.org/updates/FEDORA-2024-6b7d840efe

Comment 5 Fedora Update System 2024-04-05 01:37:44 UTC

FEDORA-2024-41295cb23c has been pushed to the Fedora 38 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-41295cb23c`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-41295cb23c

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2024-04-05 01:39:56 UTC

FEDORA-2024-6b7d840efe has been pushed to the Fedora 40 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-6b7d840efe`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-6b7d840efe

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2024-04-05 02:02:56 UTC

FEDORA-2024-7dd4b3b9a4 has been pushed to the Fedora 39 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-7dd4b3b9a4`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-7dd4b3b9a4

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 8 Fedora Update System 2024-04-05 23:10:19 UTC

FEDORA-2024-6b7d840efe (kernel-6.8.4-300.fc40 and kernel-headers-6.8.3-300.fc40) has been pushed to the Fedora 40 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 9 Fedora Update System 2024-04-06 01:41:29 UTC

FEDORA-2024-7dd4b3b9a4 (kernel-6.8.4-200.fc39 and kernel-headers-6.8.3-200.fc39) has been pushed to the Fedora 39 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 10 Fedora Update System 2024-04-06 03:13:36 UTC

FEDORA-2024-41295cb23c (kernel-6.8.4-100.fc38 and kernel-headers-6.8.3-100.fc38) has been pushed to the Fedora 38 stable repository.
If problem still persists, please make note of it in this bug report.