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author | NeilBrown <neilb@suse.com> | 2017-12-19 10:01:47 +1100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-08 16:03:44 +0100 |
commit | dbeccabf5294e80f7cc9ee566746c42211bed736 (patch) | |
tree | 1485413f0661ce4cac9561c98f5156396cbe538b /drivers/staging/lustre | |
parent | 213b14b1fa55790f55b180ed5121b07f037c7ddd (diff) | |
download | linux-stable-dbeccabf5294e80f7cc9ee566746c42211bed736.tar.gz linux-stable-dbeccabf5294e80f7cc9ee566746c42211bed736.tar.bz2 linux-stable-dbeccabf5294e80f7cc9ee566746c42211bed736.zip |
staging: lustre: disable preempt while sampling processor id.
Calling smp_processor_id() without disabling preemption
triggers a warning (if CONFIG_DEBUG_PREEMPT).
I think the result of cfs_cpt_current() is only used as a hint for
load balancing, rather than as a precise and stable indicator of
the current CPU. So it doesn't need to be called with
preemption disabled.
So disable preemption inside cfs_cpt_current() to silence the warning.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/lustre')
-rw-r--r-- | drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c b/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c index ae306c9c3c78..2f5d8f300ef5 100644 --- a/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c +++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c @@ -529,19 +529,20 @@ EXPORT_SYMBOL(cfs_cpt_spread_node); int cfs_cpt_current(struct cfs_cpt_table *cptab, int remap) { - int cpu = smp_processor_id(); - int cpt = cptab->ctb_cpu2cpt[cpu]; + int cpu; + int cpt; - if (cpt < 0) { - if (!remap) - return cpt; + preempt_disable(); + cpu = smp_processor_id(); + cpt = cptab->ctb_cpu2cpt[cpu]; + if (cpt < 0 && remap) { /* don't return negative value for safety of upper layer, * instead we shadow the unknown cpu to a valid partition ID */ cpt = cpu % cptab->ctb_nparts; } - + preempt_enable(); return cpt; } EXPORT_SYMBOL(cfs_cpt_current); |