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Who When What Removed Added
Red Hat Bugzilla 2020-08-23 02:45:19 UTC Pool ID sst_platform_tools_rhel_8
Carlos O'Donell 2020-08-25 20:15:37 UTC Assignee glibc-bugzilla pfrankli
Carlos O'Donell 2020-09-08 20:40:45 UTC Blocks 1877115
Carlos O'Donell 2020-09-10 04:50:08 UTC Doc Type If docs needed, set a value Enhancement
Carlos O'Donell 2020-09-10 04:59:31 UTC Status NEW ASSIGNED
Sergey Kolosov 2020-09-17 07:16:25 UTC CC skolosov
Martin Cermak 2020-10-01 14:54:59 UTC CC mcermak
Patsy Griffin 2020-10-04 16:19:23 UTC Doc Text Feature:
Performance improvements for IBM zSeries.

Reason:
Instructions (pfd) intended to improve copies greater than or equal to 64kb were being used for smaller copies, resulting in slower performance for smaller memcpy functions.

In the case of memset, the 256b-mvc was relying on the result of the previous 256b-mvc rather than just a stc which was counterproductive.

Result:
For memcpy, less than 64kb we now use a loop rather than the
pfd instructions.
For memset, we replaced the dependency on 256b-mvc with a stc instruction.
Patsy Griffin 2020-10-04 16:20:31 UTC Status ASSIGNED MODIFIED
Fixed In Version glibc-2.28-131.el8
Florian Weimer 2020-10-05 08:11:56 UTC CC sipoyare
Patsy Griffin 2020-10-05 15:09:24 UTC Doc Text Feature:
Performance improvements for IBM zSeries.

Reason:
Instructions (pfd) intended to improve copies greater than or equal to 64kb were being used for smaller copies, resulting in slower performance for smaller memcpy functions.

In the case of memset, the 256b-mvc was relying on the result of the previous 256b-mvc rather than just a stc which was counterproductive.

Result:
For memcpy, less than 64kb we now use a loop rather than the
pfd instructions.
For memset, we replaced the dependency on 256b-mvc with a stc instruction.
Feature:
Performance improvements for IBM zSeries.

Reason:
Applications working with in-memory data could see
less than acceptable performance for small pieces of data (< 64KiB)."

Result:
The core library implementation for the memcpy
and memset APIs were adjusted to accelerate small data copies (< 64KiB)
and likewise larger data copies were adjusted. Applications working
with in-memory data should see significantly improved preformance across
a wide variety of workloads
Red Hat One Jira (issues.redhat.com) 2020-10-14 13:52:50 UTC Link ID Red Hat Issue Tracker - Private RHELPLAN-51913
Valentina Mukhamedzhanova 2020-10-14 15:51:06 UTC CC vmukhame
Martin Cermak 2020-10-16 08:21:08 UTC QA Contact qe-baseos-tools-bugs skolosov
errata-xmlrpc 2020-10-27 07:34:38 UTC Status MODIFIED ON_QA
Petr Kovar 2020-11-03 12:33:31 UTC Docs Contact zzoubkov
Sergey Kolosov 2020-11-06 20:12:59 UTC Status ON_QA VERIFIED
Zuzana Zoubkova 2020-11-26 13:47:24 UTC Flags needinfo?(pfrankli)
Patsy Griffin 2020-11-26 13:56:00 UTC Flags needinfo?(pfrankli) needinfo?(codonell)
Florian Weimer 2020-11-26 14:07:58 UTC Summary glibc: Improve IBM zSeries (s390x) Performance glibc: Improve IBM Z (s390x) Performance
Carlos O'Donell 2020-11-27 18:06:53 UTC Flags needinfo?(codonell)
Carlos O'Donell 2020-11-27 18:07:18 UTC Keywords FutureFeature
Type Bug Enhancement
Zuzana Zoubkova 2020-11-30 10:26:43 UTC Doc Text Feature:
Performance improvements for IBM zSeries.

Reason:
Applications working with in-memory data could see
less than acceptable performance for small pieces of data (< 64KiB)."

Result:
The core library implementation for the memcpy
and memset APIs were adjusted to accelerate small data copies (< 64KiB)
and likewise larger data copies were adjusted. Applications working
with in-memory data should see significantly improved preformance across
a wide variety of workloads
.Optimized performance of `memcpy` and `memset` on IBM Z

With this enhancement, the core library implementation for the `memcpy` and `memset` APIs were adjusted to accelerate both small (< 64KiB) and larger data copies on IBM Z processors. As a result, applications working with in-memory data now benefit from significantly improved performance across a wide variety of workloads.
Matt Newsome 2021-03-18 11:13:59 UTC Keywords Triaged
errata-xmlrpc 2021-05-18 00:31:04 UTC Status VERIFIED RELEASE_PENDING
errata-xmlrpc 2021-05-18 14:36:39 UTC Status RELEASE_PENDING CLOSED
Resolution --- ERRATA
Last Closed 2021-05-18 14:36:39 UTC
Pavel Najman 2021-09-17 12:24:26 UTC Pool ID sst_platform_tools_rhel_8 sst_pt_pcp_rhel_8
Pavel Najman 2021-09-17 12:34:06 UTC Pool ID sst_pt_pcp_rhel_8 sst_pt_gcc_glibc_rhel_8
Mark O'Brien 2023-07-18 14:30:35 UTC Pool ID sst_pt_glibc_rhel_8 sst_pt_libraries_rhel_8

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