Bug 2085529

Summary:	glibc: Restartable sequences interfaces and sched_getcpu accelerated by default
Product:	Red Hat Enterprise Linux 9	Reporter:	Florian Weimer <fweimer>
Component:	glibc	Assignee:	Florian Weimer <fweimer>
Status:	CLOSED ERRATA	QA Contact:	Sergey Kolosov <skolosov>
Severity:	medium	Docs Contact:	Dominik <dklon>
Priority:	medium
Version:	9.1	CC:	ashankar, codonell, dj, dklon, fweimer, gfialova, mnewsome, pfrankli, sipoyare
Target Milestone:	rc	Keywords:	FutureFeature, Patch, Triaged, ZStream
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	glibc-2.34-37.el9	Doc Type:	Enhancement
Doc Text:	.Applications can use the restartable sequence features through the new `glibc` interfaces To accelerate the `sched_getcpu` function (especially on aarch64), it is necessary to use the restartable sequences (rseq) kernel feature by default in `glibc`. To allow applications to continuously use the shared rseq area, `glibc` now provides the `pass:[__rseq_offset]`, `pass:[__rseq_size]` and `pass:[__rseq_flags]` symbols which were first added in `glibc` 2.35 upstream version. With this enhancement, the performance of the `sched_getcpu` function is increased and applications can now use the restartable sequence features through the new `glibc` interfaces.	Story Points:	---
Clone Of:
Clones:	2115828 (view as bug list)		Environment:
Last Closed:	2022-11-15 11:11:50 UTC	Type:	Enhancement
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2033446
Bug Blocks:	2105220, 2115828

Description Florian Weimer 2022-05-13 15:25:44 UTC

Once criu supports rseq (bug 2033446), we can enable its use by default in glibc, following partial enablement in bug 2024347.

We should consider ways to simplify integration of third-party rseq-using components such as tcmalloc. The most straightforward way to achieve that could involve backporting the GLIBC_2.35 ld.so symbols (which constitutes the entire GLIBC_2.35 symbol set for ld.so).

Comment 14 errata-xmlrpc 2022-11-15 11:11:50 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (glibc bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2022:8272