HOWTO: expand the cpumask explanation a bit

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index 99cbaea37eb760dca27875eab9bcb8bd9def2292..7e706aba1481e68c97fbb66e57a85ccc28649b8c 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -466,7 +466,9 @@ ratecycle=int       Average bandwidth for 'rate' and 'ratemin' over this number
                of milliseconds.
 
 cpumask=int    Set the CPU affinity of this job. The parameter given is a
-               bitmask of allowed CPU's the job may run on. See man
+               bitmask of allowed CPU's the job may run on. So if you want
+               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.