From 9e3e27c4e32c02e93d9779e41356adfb357957e3 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 11 Nov 2019 10:49:16 +0100 Subject: linux: Add comment on affinity set sizes to tst-skeleton-affinity.c Change-Id: Ic6ec48f75f3a0576d3121befd04531382c92afb4 --- sysdeps/unix/sysv/linux/tst-skeleton-affinity.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'sysdeps/unix/sysv/linux') diff --git a/sysdeps/unix/sysv/linux/tst-skeleton-affinity.c b/sysdeps/unix/sysv/linux/tst-skeleton-affinity.c index 32fb94cdde..9d1f27fea9 100644 --- a/sysdeps/unix/sysv/linux/tst-skeleton-affinity.c +++ b/sysdeps/unix/sysv/linux/tst-skeleton-affinity.c @@ -264,6 +264,11 @@ do_test (void) struct conf conf; setup_conf (&conf); + /* Note: The CPU set size in bits can be less than the CPU count + (and the maximum test CPU) because the userspace interface rounds + up the bit count, and the rounded-up buffer size is passed into + the kernel. The kernel does not know that some of the buffer are + actually padding, and writes data there. */ printf ("info: Detected CPU set size (in bits): %d\n", conf.set_size); printf ("info: Maximum test CPU: %d\n", conf.last_cpu); if (conf.set_size < 0 || conf.last_cpu < 0) -- cgit 1.4.1