lkml.org 
[lkml]   [2023]   [Jun]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 00/25] Add perf support to the rockchip-dfi driver
Hi,

On Wed, Jun 14, 2023 at 07:51:21PM +0000, Vincent Legoll wrote:
> 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 saw it multiple times (4 or 5) within a few tries (I guess around
20). I could see it with and without applying load on the memory.
Tests have been running globally for a second using 'sleep 1' (just
like the example from Sascha Hauer in the perf patch)

> BTW, it's on a musl-libc arm64 void linux userspace.

In my case it's Debian unstable.

-- Sebastian
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2023-06-15 00:18    [W:0.059 / U:0.748 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site