On 26/4/2019 11:29 AM, Burakov, Anatoly wrote:
On 26-Apr-19 9:44 AM, David Hunt wrote:
Coverity complains about the return of a value that may
possibly overflow because of a multiply. Limit the value
so it cannot overflow.
Coverity issue: 337677
Fixes: 4b1a631b8a ("examples/vm_power: add oob monitoring functions")
CC: sta...@dpdk.org
Signed-off-by: David Hunt <david.h...@intel.com>
---
examples/vm_power_manager/oob_monitor_x86.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/examples/vm_power_manager/oob_monitor_x86.c
b/examples/vm_power_manager/oob_monitor_x86.c
index ebd96b205..2074eec1e 100644
--- a/examples/vm_power_manager/oob_monitor_x86.c
+++ b/examples/vm_power_manager/oob_monitor_x86.c
@@ -99,7 +99,10 @@ apply_policy(int core)
return -1.0;
}
- ratio = (float)miss_diff * (float)100 / (float)hits_diff;
+ ratio = (float)miss_diff / (float)hits_diff;
+ if (ratio > 1.0)
+ ratio = 1.0;
+ ratio *= 100.0f;
It should probably be the other way around - multiply first, then
clamp. Also, please use RTE_MIN.
if (ratio < ci->branch_ratio_threshold)
power_manager_scale_core_min(core);
Anatoly and myself have spendt some time analysing the coverity issue
just now, and we have come to the conclusion that it's a false positive.
We also think it may be an issue with coverity, so for the moment I'll
mark the coverity issue as a false positive.
