sched/debug: Fix printing large integers on 32-bit platforms
Commit-ID: 13e099d2f77e1da3e4046860c48d956588633613 Gitweb: http://git.kernel.org/tip/13e099d2f77e1da3e4046860c48d956588633613 Author: Peter Zijlstra <[email protected]> AuthorDate: Mon, 14 May 2012 14:34:00 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 14 May 2012 15:05:28 +0200
sched/debug: Fix printing large integers on 32-bit platforms
Some numbers like nr_running and nr_uninterruptible are fundamentally unsigned since its impossible to have a negative amount of tasks, yet we still print them as signed to easily recognise the underflow condition.
rq->nr_uninterruptible has 'special' accounting and can in fact very easily become negative on a per-cpu basis.
It was noted that since the P() macro assumes things are long long and the promotion of unsigned 'int/long' to long long on 32bit doesn't sign extend we print silly large numbers instead of the easier to read signed numbers.
Therefore extend the P() macro to not require the sign extention.
Reported-by Diwakar Tundlam <[email protected]>
Signed-off-by Peter Zijlstra <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
--- kernel/sched/debug.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-)
kernel/sched/debug.c +8 -2
@@ -260,8 +260,14 @@ static void print_cpu(struct seq_file *m, int cpu)SEQ_printf (m,"\ncpu#%d\n" , cpu);#endif -#define P (x) \ - SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x)) +#define P (x) \ +do { \ + if (sizeof(rq->x) == 4) \ + SEQ_printf(m, " .%-30s: %ld\n", #x, (long)(rq->x)); \ + else \ + SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x));\ +} while (0) +#define PN (x) \ SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))