[PATCH 1/2] tools/power turbostat: Fix bogus SysWatt for forked program
From: Zhang Rui
Date: Tue Jun 17 2025 - 08:50:02 EST
Similar to delta_cpu(), delta_platform() is called in turbostat main
loop. This ensures accurate SysWatt readings in periodic monitoring mode
$ sudo turbostat -S -q --show power -i 1
CoreTmp PkgTmp PkgWatt CorWatt GFXWatt RAMWatt PKG_% RAM_% SysWatt
60 61 6.21 1.13 0.16 0.00 0.00 0.00 13.07
58 61 6.00 1.07 0.18 0.00 0.00 0.00 12.75
58 61 5.74 1.05 0.17 0.00 0.00 0.00 12.22
58 60 6.27 1.11 0.24 0.00 0.00 0.00 13.55
However, delta_platform() is missing for forked program and causes bogus
SysWatt reporting,
$ sudo turbostat -S -q --show power sleep 1
1.004736 sec
CoreTmp PkgTmp PkgWatt CorWatt GFXWatt RAMWatt PKG_% RAM_% SysWatt
57 58 6.05 1.02 0.16 0.00 0.00 0.00 0.03
Add missing delta_platform() for forked program.
Fixes: e5f687b89bc2 ("tools/power turbostat: Add RAPL psys as a built-in counter")
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Reviewed-by: Len Brown <len.brown@xxxxxxxxx>
---
tools/power/x86/turbostat/turbostat.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 5230e072e414..5f8ab899b552 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -9817,6 +9817,7 @@ int fork_it(char **argv)
timersub(&tv_odd, &tv_even, &tv_delta);
if (for_all_cpus_2(delta_cpu, ODD_COUNTERS, EVEN_COUNTERS))
fprintf(outf, "%s: Counter reset detected\n", progname);
+ delta_platform(&platform_counters_odd, &platform_counters_even);
compute_average(EVEN_COUNTERS);
format_all_counters(EVEN_COUNTERS);
--
2.43.0