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Bug 1913750 - glibc: memcpy calls are slower for AMD processors on RHEL 8 than RHEL 7 [rhel-8.3.0.z]
Summary: glibc: memcpy calls are slower for AMD processors on RHEL 8 than RHEL 7 [rhel...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: glibc
Version: 8.2
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: 8.0
Assignee: Florian Weimer
QA Contact: qe-baseos-tools-bugs
URL:
Whiteboard:
: 1890830 (view as bug list)
Depends On: 1880670
Blocks: 1913656
TreeView+ depends on / blocked
 
Reported: 2021-01-07 14:06 UTC by RHEL Program Management Team
Modified: 2024-06-13 23:51 UTC (History)
23 users (show)

Fixed In Version: glibc-2.28-127.el8_3.2
Doc Type: Bug Fix
Doc Text:
Cause: On x86-64, the glibc implementation of string functions wrongly estimated the amount of last-level cache available to a thread. Consequence: Calling memcpy on large buffers could negatively impact overall cache performance of the system, or the memcpy call itself could be slow. Fix: The last-level cache size is no longer scaled with the number of reported hardware threads in the system. Result: The string functions bypass caches for large buffers (and only for large buffer), avoiding undue cache impact on the rest of the system.
Clone Of: 1880670
Environment:
Last Closed: 2021-02-16 14:36:33 UTC
Type: Bug
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Knowledge Base (Solution) 5514711 0 None None None 2021-01-14 01:32:47 UTC

Comment 5 Florian Weimer 2021-01-13 12:49:29 UTC 
*** Bug 1890830 has been marked as a duplicate of this bug. ***
Comment 11 errata-xmlrpc 2021-02-16 14:36:33 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-2021:0556
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