| Message ID | 20230606080229.65029-1-andrea.righi@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [M:lowlatency] UBUNTU: [Config] lowlatency: enhance desktop responsiveness | expand |
Ack, will apply to the upload I am preparing. On Tue, 6 Jun 2023 at 09:03, Andrea Righi <andrea.righi@canonical.com> wrote: > > BugLink: https://bugs.launchpad.net/bugs/2023007 > > Enable the following kernel configs to make the lowlatency kernel more > suitable for a desktop-oriented context and give access to additional > run-time / boot-time user-space settings: > > - CONFIG_NO_HZ_FULL=y: enable access to "Full tickless mode" (shutdown > clock tick when possible across all the enabled CPUs if they are > either idle or running 1 task - reduce kernel jitter of running tasks > due to the periodic clock tick, must be enabled at boot time passing > `nohz_full=<cpu_list>`) > > - CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y: move RCU > callbacks from softirq context to kthread context (reduce time spent > in softirqs with preemption disabled to improve the overall system > responsiveness, at the cost of introducing a potential performance > penalty, because RCU callbacks are now processed by kernel threads) > > - CONFIG_RCU_LAZY=y: batch RCU callbacks and then flush them after a > timed delay instead of executing them immediately (can provide 5~10% > power-savings for idle or lightly-loaded systems, this is extremely > useful for laptops / portable devices [1]) > > [1] https://lore.kernel.org/lkml/20221016162305.2489629-3-joel@joelfernandes.org/ > > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> > --- > debian.lowlatency/config/annotations | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/debian.lowlatency/config/annotations b/debian.lowlatency/config/annotations > index fef2202364bc..737a55be4ae2 100644 > --- a/debian.lowlatency/config/annotations > +++ b/debian.lowlatency/config/annotations > @@ -15,15 +15,35 @@ CONFIG_HZ_250 note<'Override default HZ used i > CONFIG_LATENCYTOP policy<{'amd64': 'y', 'arm64': 'y'}> > CONFIG_LATENCYTOP note<'https://lists.ubuntu.com/archives/kernel-team/2014-July/045006.html, LP#1655986'> > > +CONFIG_NO_HZ_FULL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_NO_HZ_FULL note<'Enable access to "Full tickless mode" (LP: #2023007)'> > + > +CONFIG_NO_HZ_IDLE policy<{'amd64': 'n', 'arm64': 'n'}> > +CONFIG_NO_HZ_IDLE note<'Disabled in favor of CONFIG_NO_HZ_FULL (LP: #2023007)'> > + > CONFIG_PREEMPT policy<{'amd64': 'y', 'arm64': 'y'}> > -CONFIG_PREEMPT note<'Enable fully preemptible kernel'> > +CONFIG_PREEMPT note<'Enable fully preemptible kernel by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > > CONFIG_PREEMPT_VOLUNTARY policy<{'amd64': 'n', 'arm64': 'n'}> > -CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model'> > +CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > + > +CONFIG_RCU_LAZY policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_LAZY note<'Batch RCU callbacks and then flush them after a timed delay instead of executing them immediately (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU note<'Move RCU callbacks from softirq context to kthread context (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL note<'Enable CONFIG_RCU_NOCB_CPU across all CPUs by default (LP: #2023007)'> > > > # ---- Annotations without notes ---- > > CONFIG_CC_VERSION_TEXT policy<{'amd64': '"x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"', 'arm64': '"aarch64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"'}> > +CONFIG_CONTEXT_TRACKING_USER policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_CONTEXT_TRACKING_USER_FORCE policy<{'amd64': 'n', 'arm64': 'n'}> > CONFIG_GCC_VERSION policy<{'amd64': '120300', 'arm64': '120300'}> > CONFIG_HZ policy<{'amd64': '1000', 'arm64': '1000'}> > +CONFIG_TICK_CPU_ACCOUNTING policy<{'amd64': '-', 'arm64': '-'}> > +CONFIG_VIRT_CPU_ACCOUNTING policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_VIRT_CPU_ACCOUNTING_GEN policy<{'amd64': 'y', 'arm64': 'y'}> > -- > 2.39.2 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
On 23/06/06 10:02AM, Andrea Righi wrote: > BugLink: https://bugs.launchpad.net/bugs/2023007 > > Enable the following kernel configs to make the lowlatency kernel more > suitable for a desktop-oriented context and give access to additional > run-time / boot-time user-space settings: > > - CONFIG_NO_HZ_FULL=y: enable access to "Full tickless mode" (shutdown > clock tick when possible across all the enabled CPUs if they are > either idle or running 1 task - reduce kernel jitter of running tasks > due to the periodic clock tick, must be enabled at boot time passing > `nohz_full=<cpu_list>`) > > - CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y: move RCU > callbacks from softirq context to kthread context (reduce time spent > in softirqs with preemption disabled to improve the overall system > responsiveness, at the cost of introducing a potential performance > penalty, because RCU callbacks are now processed by kernel threads) > > - CONFIG_RCU_LAZY=y: batch RCU callbacks and then flush them after a > timed delay instead of executing them immediately (can provide 5~10% > power-savings for idle or lightly-loaded systems, this is extremely > useful for laptops / portable devices [1]) > > [1] https://lore.kernel.org/lkml/20221016162305.2489629-3-joel@joelfernandes.org/ > > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> > --- > debian.lowlatency/config/annotations | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/debian.lowlatency/config/annotations b/debian.lowlatency/config/annotations > index fef2202364bc..737a55be4ae2 100644 > --- a/debian.lowlatency/config/annotations > +++ b/debian.lowlatency/config/annotations > @@ -15,15 +15,35 @@ CONFIG_HZ_250 note<'Override default HZ used i > CONFIG_LATENCYTOP policy<{'amd64': 'y', 'arm64': 'y'}> > CONFIG_LATENCYTOP note<'https://lists.ubuntu.com/archives/kernel-team/2014-July/045006.html, LP#1655986'> > > +CONFIG_NO_HZ_FULL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_NO_HZ_FULL note<'Enable access to "Full tickless mode" (LP: #2023007)'> > + > +CONFIG_NO_HZ_IDLE policy<{'amd64': 'n', 'arm64': 'n'}> > +CONFIG_NO_HZ_IDLE note<'Disabled in favor of CONFIG_NO_HZ_FULL (LP: #2023007)'> > + > CONFIG_PREEMPT policy<{'amd64': 'y', 'arm64': 'y'}> > -CONFIG_PREEMPT note<'Enable fully preemptible kernel'> > +CONFIG_PREEMPT note<'Enable fully preemptible kernel by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > > CONFIG_PREEMPT_VOLUNTARY policy<{'amd64': 'n', 'arm64': 'n'}> > -CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model'> > +CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > + > +CONFIG_RCU_LAZY policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_LAZY note<'Batch RCU callbacks and then flush them after a timed delay instead of executing them immediately (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU note<'Move RCU callbacks from softirq context to kthread context (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL note<'Enable CONFIG_RCU_NOCB_CPU across all CPUs by default (LP: #2023007)'> > > > # ---- Annotations without notes ---- > > CONFIG_CC_VERSION_TEXT policy<{'amd64': '"x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"', 'arm64': '"aarch64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"'}> > +CONFIG_CONTEXT_TRACKING_USER policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_CONTEXT_TRACKING_USER_FORCE policy<{'amd64': 'n', 'arm64': 'n'}> > CONFIG_GCC_VERSION policy<{'amd64': '120300', 'arm64': '120300'}> > CONFIG_HZ policy<{'amd64': '1000', 'arm64': '1000'}> > +CONFIG_TICK_CPU_ACCOUNTING policy<{'amd64': '-', 'arm64': '-'}> > +CONFIG_VIRT_CPU_ACCOUNTING policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_VIRT_CPU_ACCOUNTING_GEN policy<{'amd64': 'y', 'arm64': 'y'}> > -- > 2.39.2 Acked-by: Andrei Gherzan <andrei.gherzan@canonical.com>
On 06.06.23 10:02, Andrea Righi wrote: > BugLink: https://bugs.launchpad.net/bugs/2023007 > > Enable the following kernel configs to make the lowlatency kernel more > suitable for a desktop-oriented context and give access to additional > run-time / boot-time user-space settings: > > - CONFIG_NO_HZ_FULL=y: enable access to "Full tickless mode" (shutdown > clock tick when possible across all the enabled CPUs if they are > either idle or running 1 task - reduce kernel jitter of running tasks > due to the periodic clock tick, must be enabled at boot time passing > `nohz_full=<cpu_list>`) > > - CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y: move RCU > callbacks from softirq context to kthread context (reduce time spent > in softirqs with preemption disabled to improve the overall system > responsiveness, at the cost of introducing a potential performance > penalty, because RCU callbacks are now processed by kernel threads) > > - CONFIG_RCU_LAZY=y: batch RCU callbacks and then flush them after a > timed delay instead of executing them immediately (can provide 5~10% > power-savings for idle or lightly-loaded systems, this is extremely > useful for laptops / portable devices [1]) > > [1] https://lore.kernel.org/lkml/20221016162305.2489629-3-joel@joelfernandes.org/ > > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> > --- Applied to This was already applied to mantic:linux-lowlatency. Thanks. -Stefan > debian.lowlatency/config/annotations | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/debian.lowlatency/config/annotations b/debian.lowlatency/config/annotations > index fef2202364bc..737a55be4ae2 100644 > --- a/debian.lowlatency/config/annotations > +++ b/debian.lowlatency/config/annotations > @@ -15,15 +15,35 @@ CONFIG_HZ_250 note<'Override default HZ used i > CONFIG_LATENCYTOP policy<{'amd64': 'y', 'arm64': 'y'}> > CONFIG_LATENCYTOP note<'https://lists.ubuntu.com/archives/kernel-team/2014-July/045006.html, LP#1655986'> > > +CONFIG_NO_HZ_FULL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_NO_HZ_FULL note<'Enable access to "Full tickless mode" (LP: #2023007)'> > + > +CONFIG_NO_HZ_IDLE policy<{'amd64': 'n', 'arm64': 'n'}> > +CONFIG_NO_HZ_IDLE note<'Disabled in favor of CONFIG_NO_HZ_FULL (LP: #2023007)'> > + > CONFIG_PREEMPT policy<{'amd64': 'y', 'arm64': 'y'}> > -CONFIG_PREEMPT note<'Enable fully preemptible kernel'> > +CONFIG_PREEMPT note<'Enable fully preemptible kernel by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > > CONFIG_PREEMPT_VOLUNTARY policy<{'amd64': 'n', 'arm64': 'n'}> > -CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model'> > +CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> > + > +CONFIG_RCU_LAZY policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_LAZY note<'Batch RCU callbacks and then flush them after a timed delay instead of executing them immediately (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU note<'Move RCU callbacks from softirq context to kthread context (LP: #2023007)'> > + > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL note<'Enable CONFIG_RCU_NOCB_CPU across all CPUs by default (LP: #2023007)'> > > > # ---- Annotations without notes ---- > > CONFIG_CC_VERSION_TEXT policy<{'amd64': '"x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"', 'arm64': '"aarch64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"'}> > +CONFIG_CONTEXT_TRACKING_USER policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_CONTEXT_TRACKING_USER_FORCE policy<{'amd64': 'n', 'arm64': 'n'}> > CONFIG_GCC_VERSION policy<{'amd64': '120300', 'arm64': '120300'}> > CONFIG_HZ policy<{'amd64': '1000', 'arm64': '1000'}> > +CONFIG_TICK_CPU_ACCOUNTING policy<{'amd64': '-', 'arm64': '-'}> > +CONFIG_VIRT_CPU_ACCOUNTING policy<{'amd64': 'y', 'arm64': 'y'}> > +CONFIG_VIRT_CPU_ACCOUNTING_GEN policy<{'amd64': 'y', 'arm64': 'y'}>
diff --git a/debian.lowlatency/config/annotations b/debian.lowlatency/config/annotations index fef2202364bc..737a55be4ae2 100644 --- a/debian.lowlatency/config/annotations +++ b/debian.lowlatency/config/annotations @@ -15,15 +15,35 @@ CONFIG_HZ_250 note<'Override default HZ used i CONFIG_LATENCYTOP policy<{'amd64': 'y', 'arm64': 'y'}> CONFIG_LATENCYTOP note<'https://lists.ubuntu.com/archives/kernel-team/2014-July/045006.html, LP#1655986'> +CONFIG_NO_HZ_FULL policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_NO_HZ_FULL note<'Enable access to "Full tickless mode" (LP: #2023007)'> + +CONFIG_NO_HZ_IDLE policy<{'amd64': 'n', 'arm64': 'n'}> +CONFIG_NO_HZ_IDLE note<'Disabled in favor of CONFIG_NO_HZ_FULL (LP: #2023007)'> + CONFIG_PREEMPT policy<{'amd64': 'y', 'arm64': 'y'}> -CONFIG_PREEMPT note<'Enable fully preemptible kernel'> +CONFIG_PREEMPT note<'Enable fully preemptible kernel by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> CONFIG_PREEMPT_VOLUNTARY policy<{'amd64': 'n', 'arm64': 'n'}> -CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model'> +CONFIG_PREEMPT_VOLUNTARY note<'Disable voluntary preemption model by default (can be changed at runtime via /sys/kernel/debug/sched/preempt)'> + +CONFIG_RCU_LAZY policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_RCU_LAZY note<'Batch RCU callbacks and then flush them after a timed delay instead of executing them immediately (LP: #2023007)'> + +CONFIG_RCU_NOCB_CPU policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_RCU_NOCB_CPU note<'Move RCU callbacks from softirq context to kthread context (LP: #2023007)'> + +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_RCU_NOCB_CPU_DEFAULT_ALL note<'Enable CONFIG_RCU_NOCB_CPU across all CPUs by default (LP: #2023007)'> # ---- Annotations without notes ---- CONFIG_CC_VERSION_TEXT policy<{'amd64': '"x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"', 'arm64': '"aarch64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1) 12.3.0"'}> +CONFIG_CONTEXT_TRACKING_USER policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_CONTEXT_TRACKING_USER_FORCE policy<{'amd64': 'n', 'arm64': 'n'}> CONFIG_GCC_VERSION policy<{'amd64': '120300', 'arm64': '120300'}> CONFIG_HZ policy<{'amd64': '1000', 'arm64': '1000'}> +CONFIG_TICK_CPU_ACCOUNTING policy<{'amd64': '-', 'arm64': '-'}> +CONFIG_VIRT_CPU_ACCOUNTING policy<{'amd64': 'y', 'arm64': 'y'}> +CONFIG_VIRT_CPU_ACCOUNTING_GEN policy<{'amd64': 'y', 'arm64': 'y'}>
BugLink: https://bugs.launchpad.net/bugs/2023007 Enable the following kernel configs to make the lowlatency kernel more suitable for a desktop-oriented context and give access to additional run-time / boot-time user-space settings: - CONFIG_NO_HZ_FULL=y: enable access to "Full tickless mode" (shutdown clock tick when possible across all the enabled CPUs if they are either idle or running 1 task - reduce kernel jitter of running tasks due to the periodic clock tick, must be enabled at boot time passing `nohz_full=<cpu_list>`) - CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y: move RCU callbacks from softirq context to kthread context (reduce time spent in softirqs with preemption disabled to improve the overall system responsiveness, at the cost of introducing a potential performance penalty, because RCU callbacks are now processed by kernel threads) - CONFIG_RCU_LAZY=y: batch RCU callbacks and then flush them after a timed delay instead of executing them immediately (can provide 5~10% power-savings for idle or lightly-loaded systems, this is extremely useful for laptops / portable devices [1]) [1] https://lore.kernel.org/lkml/20221016162305.2489629-3-joel@joelfernandes.org/ Signed-off-by: Andrea Righi <andrea.righi@canonical.com> --- debian.lowlatency/config/annotations | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-)