Re: [PATCH V4 4/8] perf/x86/intel/uncore: add new data structures for free running counters

From: Thomas Gleixner
Date: Sun Jan 14 2018 - 15:52:57 EST


On Sun, 14 Jan 2018, Thomas Gleixner wrote:

> On Thu, 2 Nov 2017, kan.liang@xxxxxxxxx wrote:
> > +/*
> > + * Free running counter is similar as fixed counter, except it is read-only
> > + * and always active when the uncore box is powered up.
> > + *
> > + * Here are the rules which are used to encode the event for free running
> > + * counter.
> > + * - The event for free running counter has the same event code 0xff as
> > + * the event for fixed counter.
> > + * - The umask of the event starts from 0x10. The umask which is less
> > + * than 0x10 is reserved for the event of fixed counter.
> > + * - The free running counters can be divided into different types according
> > + * to the MSR location, bit width or definition. The start point of the
> > + * umask for different type has 0x10 offset.
> > + *
> > + * For example, there are three types of IIO free running counters on Skylake
> > + * server, IO CLOCKS counters, BANDWIDTH counters and UTILIZATION counters.
> > + * The event code for all the free running counters is 0xff.
> > + * 'ioclk' is the first counter of IO CLOCKS. IO CLOCKS is the first type,
> > + * which umask starts from 0x10.
> > + * So 'ioclk' is encoded as event=0xff,umask=0x10
> > + * 'bw_in_port2' is the third counter of BANDWIDTH counters. BANDWIDTH is
> > + * the second type, which umask starts from 0x20.
> > + * So 'bw_in_port2' is encoded as event=0xff,umask=0x22
> > + */
> > +static inline unsigned int uncore_freerunning_idx(u64 config)
> > +{
> > + return ((config >> 8) & 0xf);
> > +}
> > +
> > +#define UNCORE_FREERUNNING_UMASK_START 0x10
> > +static inline unsigned int uncore_freerunning_type(u64 config)
>
> Groan. I asked that before that you please stop glueing defines right in
> front of a function declaration w/o any visible space. Is it that hard to
> read and address _ALL_ review comments?
>
> > +{
> > + return ((((config >> 8) - UNCORE_FREERUNNING_UMASK_START) >> 4) & 0xf);
> > +}
>
> Other than that this looks reasonable.

Hit send to early:

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>