Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1480624

Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu topology for ITMT

Show all headers | View raw

On Thu, 8 Sep 2016, Srinivas Pandruvada wrote:
> From: Tim Chen <tim.c.chen@linux.intel.com>
> 
> We uses ASYM_PACKING feature in the scheduler to move tasks to more
> capable cpus that can be boosted to higher frequency. This is enabled by
> Intel Turbo Boost Max Technology 3.0 (ITMT).  We mark the sched domain
> topology level with SD_ASYM_PACKING flag for such systems to indicate
> scheduler can use the ASYM_PACKING feature to move load to the
> more capable cpus.

Sigh. This changelog does not tell anything about the nature of the patch,
the rationale for it etc. It's just a meaningless blurb.


> +unsigned int __read_mostly sysctl_sched_itmt_enabled;
> +
>  static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
>  {
>  	unsigned long flags;
> @@ -471,31 +473,57 @@ static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
>  	return false;
>  }
>  
> -static struct sched_domain_topology_level numa_inside_package_topology[] = {
> +#ifdef CONFIG_SCHED_ITMT
> +static int x86_core_flags(void)
> +{
> +	int flags = cpu_core_flags();
> +
> +	if (sysctl_sched_itmt_enabled)
> +		flags |= SD_ASYM_PACKING;
> +
> +	return flags;
> +}
> +
> +static int x86_smt_flags(void)
> +{
> +	int flags = cpu_smt_flags();
> +
> +	if (sysctl_sched_itmt_enabled)
> +		flags |= SD_ASYM_PACKING;
> +
> +	return flags;
> +}
> +#else
> +#define x86_core_flags cpu_core_flags
> +#define x86_smt_flags cpu_smt_flags
> +#endif

No. We first rework the code so that the IMT stuff can be added in a later
patch easily.

Thanks,

	tglx

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu  topology for ITMT Thomas Gleixner <tglx@linutronix.de> - 2016-09-10 15:20 +0200
  Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu  topology for ITMT Tim Chen <tim.c.chen@linux.intel.com> - 2016-09-12 23:00 +0200
    Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu  topology for ITMT Peter Zijlstra <peterz@infradead.org> - 2016-09-13 09:30 +0200
      Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu  topology for ITMT Jiri Olsa <jolsa@redhat.com> - 2016-09-19 11:20 +0200
        Re: [PATCH v3 1/8] sched, x86: Add SD_ASYM_PACKING flags to x86 cpu  topology for ITMT Tim Chen <tim.c.chen@linux.intel.com> - 2016-09-19 18:10 +0200

csiph-web