2013-03-28 02:55:10

by Xie XiuQi

Subject: [PATCH] ia64: Fix example error_injection_tool

I got a "sched_setaffinity:: Invalid argument" error when using
err_injection_tool to inject error on a system with over 32 cpus.

Error information when injecting an error on a system with over 32 cpus:
$ ./err_injection_tool -i
/sys/devices/system/cpu/cpu0/err_inject//err_type_info
Begine at Tue Mar 26 11:20:08 2013
Configurations:
On cpu32: loop=10, interval=5(s) err_type_info=4101,err_struct_info=95
Error sched_setaffinity:: Invalid argument
All done

This because there is overflow when calculating the cpumask: the
type of (1<<k) is int, while mask[j] is unsigned long. When k > 31,
(1<<k) is truncated to ZERO, resulting in a unexpected cpumask.

Signed-off-by: Xie XiuQi <[email protected]>
---
Documentation/ia64/err_inject.txt | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Documentation/ia64/err_inject.txt b/Documentation/ia64/err_inject.txt
index 223e4f0..ec61ac1 100644
--- a/Documentation/ia64/err_inject.txt
+++ b/Documentation/ia64/err_inject.txt
@@ -882,7 +882,7 @@ int err_inj()
cpu=parameters[i].cpu;
k = cpu%64;
j = cpu/64;
- mask[j]=1<<k;
+ mask[j] = (unsigned long)1<<k;

if (sched_setaffinity(0, MASK_SIZE*8, mask)==-1) {
perror("Error sched_setaffinity:");
--
1.6.0.2

2013-03-28 16:47:23

by Luck, Tony

Subject: RE: [PATCH] ia64: Fix example error_injection_tool

Nice catch.

- mask[j]=1<<k;
+ mask[j] = (unsigned long)1<<k;

Could use
mask[j] = 1ul << k;
to avoid the verbose cast.

-Tony

2013-03-29 01:24:52

by Xie XiuQi

Subject: Re: [PATCH] ia64: Fix example error_injection_tool

On 2013/3/29 0:47, Luck, Tony wrote:
> Nice catch.
>
> - mask[j]=1<<k;
> + mask[j] = (unsigned long)1<<k;
>
> Could use
> mask[j] = 1ul << k;
> to avoid the verbose cast.

Thank you for your suggestion, Tony.
I'll modify it in next version.

>
> -Tony
>
>