Messages in this thread | | | From | Vincent Legoll <> | Date | Wed, 14 Jun 2023 19:51:21 +0000 | Subject | Re: [PATCH v5 00/25] Add perf support to the rockchip-dfi driver |
| |
Hi,
On Wed, Jun 14, 2023 at 3:27 PM Sebastian Reichel <sebastian.reichel@collabora.com> wrote: > On Wed, Jun 14, 2023 at 03:40:34PM +0200, Sebastian Reichel wrote: > > I tested the series on RK3588 EVB1. The read/write byts looks > > sensible. Sometimes cycles reads unrealistic values, though: > > > > 18446744070475110400 rockchip_ddr/cycles/ > > I have seen this going off a few times with and without memory > pressure. If it's way off, it always seems to follow the same > pattern: The upper 32 bits are 0xffffffff instead of 0x00000000 > with the lower 32 bits containing sensible data.
How often is that happening ?
I have been running this in a loop with varying sleep duration for the last few hours without hitting it, with and without memtester.
REPEATS=1000 MAX_DURATION=100
OUT="/tmp/perf-dfi-rk3588-${REPEATS}x${MAX_DURATION}s.txt" echo -n > $OUT
for i in $(seq $REPEATS) ; do DURATION=$(shuf -i "0-${MAX_DURATION}" -n 1) echo -n "${DURATION} : " >> $OUT perf stat -a -e rockchip_ddr/cycles/ sleep $DURATION 2>&1 | awk '/rockchip_ddr/ {printf("%X\n", int($1))}' >> $OUT done
BTW, it's on a musl-libc arm64 void linux userspace.
-- Vincent Legoll
| |