From 6be53520ad8f87dc748f381e4e8e6a846a4b466b Mon Sep 17 00:00:00 2001 From: Dou Liyang Date: Mon, 9 Oct 2017 17:03:33 +0800 Subject: x86/tsc: Append the 'tsc=' description for the 'tsc=unstable' boot parameter Commit: 8309f86cd41e ("x86/tsc: Provide 'tsc=unstable' boot parameter") added a new 'tsc=unstable' parameter, but didn't document it. Document it. Signed-off-by: Dou Liyang Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Cc: Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1507539813-11420-1-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 05496622b4ef..6b99c8b77c59 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4194,6 +4194,9 @@ Used to run time disable IRQ_TIME_ACCOUNTING on any platforms where RDTSC is slow and this accounting can add overhead. + [x86] unstable: mark the TSC clocksource as unstable, this + marks the TSC unconditionally unstable at bootup and + avoids any further wobbles once the TSC watchdog notices. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface -- cgit From b0d40d2b22fe48cfcbbfb137fd198be0a1cd8a85 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 31 Oct 2017 04:18:34 +0100 Subject: sched/isolation: Document isolcpus= boot parameter flags, mark it deprecated Document the latest updates on the isolcpus= boot option. While at it, let's also fix the details about the preferred way to isolate a set of CPUs from the scheduler general domains. Cpusets offer a much better interface to achieve that. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Acked-by: Peter Zijlstra Cc: Chris Metcalf Cc: Christoph Lameter Cc: Linus Torvalds Cc: Luiz Capitulino Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Rik van Riel Cc: Wanpeng Li Link: http://lkml.kernel.org/r/1509419914-16179-1-git-send-email-frederic@kernel.org [ Clarified the text some more, marked the boot option deprecated. ] Signed-off-by: Ingo Molnar --- Documentation/admin-guide/kernel-parameters.txt | 39 ++++++++++++++++--------- 1 file changed, 26 insertions(+), 13 deletions(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6b99c8b77c59..17eb0234d5be 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1727,20 +1727,33 @@ isapnp= [ISAPNP] Format: ,,, - isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. - The argument is a cpu list, as described above. + isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance. + [Deprecated - use cpusets instead] + Format: [flag-list,] + + Specify one or more CPUs to isolate from disturbances + specified in the flag list (default: domain): + + nohz + Disable the tick when a single task runs. + domain + Isolate from the general SMP balancing and scheduling + algorithms. Note that performing domain isolation this way + is irreversible: it's not possible to bring back a CPU to + the domains once isolated through isolcpus. It's strongly + advised to use cpusets instead to disable scheduler load + balancing through the "cpuset.sched_load_balance" file. + It offers a much more flexible interface where CPUs can + move in and out of an isolated set anytime. + + You can move a process onto or off an "isolated" CPU via + the CPU affinity syscalls or cpuset. + begins at 0 and the maximum value is + "number of CPUs in system - 1". + + The format of is described above. + - This option can be used to specify one or more CPUs - to isolate from the general SMP balancing and scheduling - algorithms. You can move a process onto or off an - "isolated" CPU via the CPU affinity syscalls or cpuset. - begins at 0 and the maximum value is - "number of CPUs in system - 1". - - This option is the preferred way to isolate CPUs. The - alternative -- manually setting the CPU mask of all - tasks in the system -- can cause problems and - suboptimal load balancer performance. iucv= [HW,NET] -- cgit