From b0ea08ce4ed567d3dff372f0866d5c3fbf1f8c39 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 5 Dec 2008 12:57:11 +0100 Subject: [PATCH 1/1] Add comment on cpumask not working with a CPU count > 32 Signed-off-by: Jens Axboe --- HOWTO | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/HOWTO b/HOWTO index 4298f324..5a55c1a2 100644 --- a/HOWTO +++ b/HOWTO @@ -583,7 +583,10 @@ cpumask=int Set the CPU affinity of this job. The parameter given is a the allowed CPUs to be 1 and 5, you would pass the decimal value of (1 << 1 | 1 << 5), or 34. See man sched_setaffinity(2). This may not work on all supported - operating systems or kernel versions. + operating systems or kernel versions. This option doesn't + work well for a higher CPU count than what you can store in + an integer mask, so it can only control cpus 1-32. For + boxes with larger CPU counts, use cpus_allowed. cpus_allowed=str Controls the same options as cpumask, but it allows a text setting of the permitted CPUs instead. So to use CPUs 1 and -- 2.25.1