lkml.org 
[lkml]   [2023]   [Jun]   [15]   [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 Sebastian,

On Wed, Jun 14, 2023 at 03:40:34PM +0200, Sebastian Reichel wrote:
> Hi,
>
> On Wed, May 24, 2023 at 10:31:28AM +0200, Sascha Hauer wrote:
> > This is v5 of the series adding perf support to the rockchip DFI driver.
> >
> > A lot has changed in the perf driver since v4. First of all the review
> > feedback from Robin and Jonathan has been integrated. The perf driver
> > now not only supports monitoring the total DDR utilization, but also the
> > individual channels. I also reworked the way the raw 32bit counter
> > values are summed up to 64bit perf values, so hopefully the code is
> > easier to follow now.
> >
> > lockdep found out that that locking in the perf driver was broken, so I
> > reworked that as well. None of the perf hooks allows locking with
> > mutexes or spinlocks, so in perf it's not possible to enable the DFI
> > controller when needed. Instead I now unconditionally enable the DFI
> > controller during probe when perf is enabled.
> >
> > Furthermore the hrtimer I use for reading out the hardware counter
> > values before they overflow race with perf. Now a seqlock is used to
> > prevent that.
> >
> > The RK3588 device tree changes for the DFI were not part of v4. As
> > Vincent Legoll showed interest in testing this series the necessary
> > device tree changes are now part of this series.
>
> I tested the series on RK3588 EVB1. The read/write byts looks
> sensible. Sometimes cycles reads unrealistic values, though:
>
> Performance counter stats for 'system wide':
>
> 18446744070475110400 rockchip_ddr/cycles/

I'll have a look later this day. I remember seeing this, but I thought
this had been resolved already.

Thanks for your feedback so far.

Sascha

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

\
 
 \ /
  Last update: 2023-06-15 08:57    [W:0.354 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site