[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#804857: marked as done (linux: New feature: enable CONFIG_NO_HZ_FULL and CONFIG_RCU_NOCB_CPU/CONFIG_RCU_NOCB_CPU_NONE)

Your message dated Mon, 15 Nov 2021 10:00:20 +0000
with message-id <E1mmYmi-000C9k-In@fasolo.debian.org>
and subject line Bug#804857: fixed in linux 5.15.2-1~exp1
has caused the Debian Bug report #804857,
regarding linux: New feature: enable CONFIG_NO_HZ_FULL and CONFIG_RCU_NOCB_CPU/CONFIG_RCU_NOCB_CPU_NONE
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact owner@bugs.debian.org
immediately.)


-- 
804857: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=804857
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems
--- Begin Message --- 
Source: linux
Severity: wishlist

Dear Maintainer,

Could you please enable kernel options CONFIG_NO_HZ_FULL, CONFIG_RCU_NOCB_CPU and CONFIG_RCU_NOCB_CPU_NONE.

As explained in: https://www.kernel.org/doc/Documentation/timers/NO_HZ.txt

This options:
 - Don't modify default kernel behavior
 - Enable kernel command line nohz_full to enable tickless cpus
 - Enable kernel command line rcu_nocbs to offload rcu callbacks

The combination of these parameters + cpu-pinning of virtual machines greatly improve performance.
It also reduces latency in these virtual machines as the host system doesn't try to use it. (if your cgroup is correctly made)

These parameters are disabled in all debian kernels.
These parameters are enabled for various linux distribution by default without problem. (rhel 7 being one of them)
  (note that rhel 7 uses CONFIG_RCU_NOCB_CPU_ALL and user can pin offload kthreads to a core)

The usage of CONFIG_RCU_NOCB_CPU_NONE doesn't offload by default. But possibly this behavior is not the best.


Quentin.

-- System Information:
Debian Release: stretch/sid
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.3.0-rc7-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

--- End Message ---
--- Begin Message --- 
Source: linux
Source-Version: 5.15.2-1~exp1
Done: Salvatore Bonaccorso <carnil@debian.org>

We believe that the bug you reported is fixed in the latest version of
linux, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 804857@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Salvatore Bonaccorso <carnil@debian.org> (supplier of updated linux package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Format: 1.8
Date: Sun, 14 Nov 2021 14:27:40 +0100
Source: linux
Architecture: source
Version: 5.15.2-1~exp1
Distribution: experimental
Urgency: medium
Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>
Changed-By: Salvatore Bonaccorso <carnil@debian.org>
Closes: 804857 911815 989285 995466 996951
Changes:
 linux (5.15.2-1~exp1) experimental; urgency=medium
 .
   * New upstream stable update:
     https://www.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.2
 .
   [ Salvatore Bonaccorso ]
   * [rt] Update to 5.15-rt17 and reenable (Closes: #995466)
   * perf srcline: Use long-running addr2line per DSO (Closes: #911815)
   * Refresh "Export symbols needed by Android drivers"
   * [rt] Update to 5.15.2-rt19
   * Input: elantench - fix misreporting trackpoint coordinates (Closes: #989285)
   * kernel/time: Enable NO_HZ_FULL (Closes: #804857)
   * io-wq: serialize hash clear with wakeup (Closes: #996951)
 .
   [ Vincent Blut ]
   * [x86] drivers/ptp: Enable PTP_1588_CLOCK_VMW as module
   * drivers/ptp: Enable PTP_1588_CLOCK_DTE, PTP_1588_CLOCK_IDT82P33,
     PTP_1588_CLOCK_IDTCM, PTP_1588_CLOCK_OCP as modules
   * drivers/ptp, net: Enable DP83640_PHY, PTP_1588_CLOCK_INES,
     NET_PTP_CLASSIFY, NETWORK_PHY_TIMESTAMPING
Checksums-Sha1:
 74ef56708169af7f69392082f89d65ed0314f0e8 203310 linux_5.15.2-1~exp1.dsc
 8424063a5cc468f6a60698f4bbf3781e8fc97b0d 127708056 linux_5.15.2.orig.tar.xz
 63dd94abfd31a2ee4eb59368794f13af2917fcde 1288828 linux_5.15.2-1~exp1.debian.tar.xz
 f65be256d83fd350693416f7fa2328f46181bee0 6399 linux_5.15.2-1~exp1_source.buildinfo
Checksums-Sha256:
 68b5e5d809d8b9a8e4e25ae36395b4714626431c0a76e618c7e9b67d0b68bfd2 203310 linux_5.15.2-1~exp1.dsc
 ff0dbe681ebc42a17622e43ac00faa1d0854b2415a83061a0bd8dbe96f340abd 127708056 linux_5.15.2.orig.tar.xz
 6d0f2b537d07eaab1b671b0e0080c35d05bc07af2e00021b6a824a5ece0c4a49 1288828 linux_5.15.2-1~exp1.debian.tar.xz
 747c9347b6293d5b455605e3d6b1ab6209f4d0eb9020753577393006f946713f 6399 linux_5.15.2-1~exp1_source.buildinfo
Files:
 e160917005445d505d4fae102ac08f38 203310 kernel optional linux_5.15.2-1~exp1.dsc
 6021fb5a178e295058dec815553c97b3 127708056 kernel optional linux_5.15.2.orig.tar.xz
 1f6832938a55dd9139a169ef3b206cfa 1288828 kernel optional linux_5.15.2-1~exp1.debian.tar.xz
 e406edc6bb4eba0184e0f24b95ea6498 6399 kernel optional linux_5.15.2-1~exp1_source.buildinfo

-----BEGIN PGP SIGNATURE-----

iQKmBAEBCgCQFiEERkRAmAjBceBVMd3uBUy48xNDz0QFAmGRDz9fFIAAAAAALgAo
aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldDQ2
NDQ0MDk4MDhDMTcxRTA1NTMxRERFRTA1NENCOEYzMTM0M0NGNDQSHGNhcm5pbEBk
ZWJpYW4ub3JnAAoJEAVMuPMTQ89EV/IP/3nmskw1msD2jLgm82VNHxj/b9oxCHo0
Sk9r/LzbAeg1pPOd1YYgyZup5gSOdnirxFd8bzSw6B/MUuiBrd30L1zuPTur47q4
qa446TtPEIHcbSQhETtgZCyzplFnbAS6jRKBZy2kiXuxzaXKO/5i+RKzSxicuPDD
+6M1MueKiKgt3wI310K+8mOx6XvjCP3wuMbSQQuvnQ7Ea0fbNvggRhaXgdvfZYvs
jYEtFQkw5Uhnn4D2XSp9dHBW3Rz/ib6HxTlCZzQm9M/qV6Oak+9+X2ZlgWuzOfcJ
XH6dqjIB1JcZAMs0YTKZrVtEr0a+FQVD+8NSWpTXu+FzruM3Ks9XugrcGaylmliq
LlXoogeEoKAxEimZU6zxJzF1jeDSw2bWMjVoimHE1C4M2drak4gFg+EWGMflbEWb
xqnbE1A2eN138BDuPi4DSwCmhSjaiGhVoB58vnrnQz+c1jJ9DBoyRLDelYSTGNrD
BuXyXd2/Crj472aGXr5RyoqWHNDWKF39s8m4XwEhUSsCUvJJ+aN5Cn8+PB1Yww9J
aArt4Ue1h1fJyy7o4rL2ZCX187KFwiQxqUoZ1IoXx9iim80N4dJTlhO/T38c//Oa
6K+MAAHywa4o9BRwoR2DiRP4j1yhzAxgYr66OGwv18ozSGja0wbaGuyxk1b2bGQq
/25zAYf1OKSi
=29M6
-----END PGP SIGNATURE-----

--- End Message ---
Reply to: