> -----Original Message----- > From: linux-fpga-owner@xxxxxxxxxxxxxxx <linux-fpga-owner@xxxxxxxxxxxxxxx> > On Behalf Of Randy Dunlap > Sent: Saturday, April 18, 2020 8:08 AM > To: Wu, Hao <hao.wu@xxxxxxxxx>; will@xxxxxxxxxx; mdf@xxxxxxxxxx; > mark.rutland@xxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; linux- > fpga@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-api@xxxxxxxxxxxxxxx; atull@xxxxxxxxxx; Xu, Yilun > <yilun.xu@xxxxxxxxx>; trix@xxxxxxxxxx; bhu@xxxxxxxxxx > Subject: Re: [PATCH v9 1/2] Documentation: fpga: dfl: add description for > performance reporting support > > Hi-- > > Here are a few comments for you: Thanks a lot for the comments, will fix all of them in the next version. : ) Hao > > On 4/16/20 10:39 PM, Wu Hao wrote: > > From: Xu Yilun <yilun.xu@xxxxxxxxx> > > > > This patch adds description for performance reporting support for > > Device Feature List (DFL) based FPGA. > > > > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx> > > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx> > > --- > > Documentation/fpga/dfl.rst | 84 > ++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 84 insertions(+) > > > > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst > > index 094fc8a..6ccaf77 100644 > > --- a/Documentation/fpga/dfl.rst > > +++ b/Documentation/fpga/dfl.rst > > > @@ -378,6 +383,85 @@ The device nodes used for ioctl() or mmap() can > be referenced through:: > > /sys/class/fpga_region/<regionX>/<dfl-port.n>/dev > > > > > > +Performance Counters > > +==================== > > +Performance reporting is one private feature implemented in FME. It > could > > +supports several independent, system-wide, device counter sets in > hardware to > > +monitor and count for performance events, including "basic", "cache", > "fabric", > > +"vtd" and "vtd_sip" counters. Users could use standard perf tool to > monitor > > +FPGA cache hit/miss rate, transaction number, interface clock counter of > AFU > > +and other FPGA performance events. > > + > > +Different FPGA devices may have different counter sets, it depends on > hardware > > sets, depending on hardware > > > +implementation. e.g. some discrete FPGA cards don't have any cache. > User could > > E.g., some > > > +use "perf list" to check which perf events are supported by target > hardware. > > + > > +In order to allow user to use standard perf API to access these > performance > > +counters, driver creates a perf PMU, and related sysfs interfaces in > > +/sys/bus/event_source/devices/dfl_fme* to describe available perf events > and > > +configuration options. > > + > > +The "format" directory describes the format of the config field of struct > > +perf_event_attr. There are 3 bitfields for config, "evtype" defines which > type > > config: "evtype" > > > +the perf event belongs to. "event" is the identity of the event within its > > belongs to; "event" is > > > +category. "portid" is introduced to decide counters set to monitor on FPGA > > category; "portid" is > > > +overall data or a specific port. > > + > > +The "events" directory describes the configuration templates for all > available > > +events which can be used with perf tool directly. For example, > fab_mmio_read > > +has the configuration "event=0x06,evtype=0x02,portid=0xff", which > shows this > > +event belongs to fabric type (0x02), the local event id is 0x06 and it is for > > +overall monitoring (portid=0xff). > > + > > +Example usage of perf:: > > + > > + $# perf list |grep dfl_fme > > + > > + dfl_fme0/fab_mmio_read/ [Kernel PMU event] > > + <...> > > + dfl_fme0/fab_port_mmio_read,portid=?/ [Kernel PMU event] > > + <...> > > + > > + $# perf stat -a -e dfl_fme0/fab_mmio_read/ <command> > > + or > > + $# perf stat -a -e dfl_fme0/event=0x06,evtype=0x02,portid=0xff/ > <command> > > + or > > + $# perf stat -a -e dfl_fme0/config=0xff2006/ <command> > > + > > +Another example, fab_port_mmio_read monitors mmio read of a specific > port. So > > +its configuration template is "event=0x06,evtype=0x01,portid=?". The > portid > > +should be explicitly set. > > + > > +Its usage of perf:: > > + > > + $# perf stat -a -e dfl_fme0/fab_port_mmio_read,portid=0x0/ <command> > > + or > > + $# perf stat -a -e dfl_fme0/event=0x06,evtype=0x02,portid=0x0/ > <command> > > + or > > + $# perf stat -a -e dfl_fme0/config=0x2006/ <command> > > + > > +Please note for fabric counters, overall perf events (fab_*) and port perf > > +events (fab_port_*) actually share one set of counters in hardware, so it > can't > > +monitor both at the same time. If this set of counters is configured to > monitor > > +overall data, then per port perf data is not supported. See below example:: > > + > > + $# perf stat -e > dfl_fme0/fab_mmio_read/,dfl_fme0/fab_port_mmio_write,\ > > + portid=0/ sleep 1 > > + > > + Performance counter stats for 'system wide': > > + > > + 3 dfl_fme0/fab_mmio_read/ > > + <not supported> dfl_fme0/fab_port_mmio_write,portid=0x0/ > > + > > + 1.001750904 seconds time elapsed > > + > > +The driver also provides a "cpumask" sysfs attribute, which contains only > one > > +cpu id used to access these perf events. Counting on multiple CPUs is not > CPU > > > +allowed since they are system-wide counters on FPGA device. > > + > > +The current driver does not support sampling. So "perf record" is > unsupported. > > + > > + > > Add new FIUs support > > ==================== > > It's possible that developers made some new function blocks (FIUs) under > this > > > > thanks. > -- > ~Randy
