lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 14 Aug 2020 12:25:24 -0700 From: Peiyong Lin <lpy@...gle.com> To: Chris Wilson <chris@...is-wilson.co.uk>, Sidath Senanayake <sidaths@...gle.com>, zzyiwei@...roid.com Cc: Amit Kucheria <amit.kucheria@...aro.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Ingo Molnar <mingo@...hat.com>, Masahiro Yamada <yamada.masahiro@...ionext.com>, Paul Walmsley <paul.walmsley@...ive.com>, Pavel Machek <pavel@....cz>, "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>, Steven Rostedt <rostedt@...dmis.org>, Ulf Hansson <ulf.hansson@...aro.org>, linux-kernel@...r.kernel.org, Prahlad Kilambi <prahladk@...gle.com>, android-kernel@...gle.com Subject: Re: [PATCH] Add power/gpu_frequency tracepoint. Hi Chris, please see my comments inline. On Fri, Aug 14, 2020 at 8:22 AM Chris Wilson <chris@...is-wilson.co.uk> wrote: > > Quoting Peiyong Lin (2020-08-13 22:03:57) > > Historically there is no common trace event for GPU frequency, in > > downstream Android each different hardware vendor implements their own > > way to expose GPU frequency, for example as a debugfs node. This patch > > standardize it as a common trace event in upstream linux kernel to help > > the ecosystem have a common implementation across hardware vendors. > > Toolings in the Linux ecosystem will benefit from this especially in the > > downstream Android, where this information is critical to graphics > > developers. > > > > Signed-off-by: Peiyong Lin <lpy@...gle.com> > > --- > > drivers/gpu/Makefile | 1 + > > drivers/gpu/trace/Kconfig | 3 +++ > > drivers/gpu/trace/Makefile | 1 + > > drivers/gpu/trace/trace_gpu_frequency.c | 13 +++++++++++++ > > include/trace/events/power.h | 26 +++++++++++++++++++++++++ > > 5 files changed, 44 insertions(+) > > create mode 100644 drivers/gpu/trace/trace_gpu_frequency.c > > > > diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile > > index 835c88318cec..f289a47eb031 100644 > > --- a/drivers/gpu/Makefile > > +++ b/drivers/gpu/Makefile > > @@ -6,3 +6,4 @@ obj-$(CONFIG_TEGRA_HOST1X) += host1x/ > > obj-y += drm/ vga/ > > obj-$(CONFIG_IMX_IPUV3_CORE) += ipu-v3/ > > obj-$(CONFIG_TRACE_GPU_MEM) += trace/ > > +obj-$(CONFIG_TRACE_GPU_FREQUENCY) += trace/ > > diff --git a/drivers/gpu/trace/Kconfig b/drivers/gpu/trace/Kconfig > > index c24e9edd022e..ac4aec8d5845 100644 > > --- a/drivers/gpu/trace/Kconfig > > +++ b/drivers/gpu/trace/Kconfig > > @@ -2,3 +2,6 @@ > > > > config TRACE_GPU_MEM > > bool > > + > > +config TRACE_GPU_FREQUENCY > > + bool > > diff --git a/drivers/gpu/trace/Makefile b/drivers/gpu/trace/Makefile > > index b70fbdc5847f..2b7ae69327d6 100644 > > --- a/drivers/gpu/trace/Makefile > > +++ b/drivers/gpu/trace/Makefile > > @@ -1,3 +1,4 @@ > > # SPDX-License-Identifier: GPL-2.0 > > > > obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o > > +obj-$(CONFIG_TRACE_GPU_FREQUENCY) += trace_gpu_frequency.o > > diff --git a/drivers/gpu/trace/trace_gpu_frequency.c b/drivers/gpu/trace/trace_gpu_frequency.c > > new file mode 100644 > > index 000000000000..f5af5800b52d > > --- /dev/null > > +++ b/drivers/gpu/trace/trace_gpu_frequency.c > > @@ -0,0 +1,13 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * GPU frequency trace points > > + * > > + * Copyright (C) 2020 Google, Inc. > > + */ > > + > > +#include <linux/module.h> > > + > > +#define CREATE_TRACE_POINTS > > +#include <trace/events/power.h> > > + > > +EXPORT_TRACEPOINT_SYMBOL(gpu_frequency); > > diff --git a/include/trace/events/power.h b/include/trace/events/power.h > > index af5018aa9517..befc0157131e 100644 > > --- a/include/trace/events/power.h > > +++ b/include/trace/events/power.h > > @@ -500,6 +500,32 @@ DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_remove_request, > > > > TP_ARGS(name, type, new_value) > > ); > > + > > +/** > > + * gpu_frequency - Reports frequency changes in GPU clock domains > > + * @state: New frequency (in KHz) > > + * @gpu_id: GPU clock domain > > + */ > > +TRACE_EVENT(gpu_frequency, > > + > > + TP_PROTO(unsigned int state, unsigned int gpu_id), > > + > > + TP_ARGS(state, gpu_id), > > + > > + TP_STRUCT__entry( > > + __field(unsigned int, state) > > + __field(unsigned int, gpu_id) > > What is a gpu-id and how are we supposed to create one? gpu_id is the id for per GPU clock domain, it should be created for per GPU clock domain. It's not necessarily tied to a physical GPU. > > 'state' is quite non-descript, and since this is not an event template > you could be a little more specific. > > So when should this tracepoint fire? For the frequency change we request, > or the frequency change of the black box of the pcu? If an implementation implements this, the GPU frequency tracepoint should be fired whenever there's a frequency change. That is to say, when gpu goes from idle to active or vice versa, or when the gpu frequency goes up and down. > > We have found that a tracepoint is not a useful monitor of the actual GPU > frequencies, for that we use provide sampling via perf-events. > -Chris
Powered by blists - more mailing lists