Hi Arnd,
On Wed, Jan 7, 2015 at 1:32 AM, Arnd Bergmann <[email protected]> wrote: > On Tuesday 06 January 2015 15:04:26 Ganapatrao Kulkarni wrote: >> On Sat, Jan 3, 2015 at 2:47 AM, Arnd Bergmann <[email protected]> wrote: >> > On Wednesday 31 December 2014 13:03:27 Ganapatrao Kulkarni wrote: >> >> + cpu@00f { >> >> + device_type = "cpu"; >> >> + compatible = "cavium,thunder", "arm,armv8"; >> >> + reg = <0x0 0x00f>; >> >> + enable-method = "psci"; >> >> + arm,associativity = <0 0 0x00f>; >> >> + }; >> >> + cpu@100 { >> >> + device_type = "cpu"; >> >> + compatible = "cavium,thunder", "arm,armv8"; >> >> + reg = <0x0 0x100>; >> >> + enable-method = "psci"; >> >> + arm,associativity = <0 0 0x100>; >> >> + }; >> > >> > What is the 0x100 offset in the last-level topology field? Does this have >> > no significance to topology at all? I would expect that to be something >> > like cluster number that is relevant to caching and should be represented >> > as a separate level. >> >> i did not understand, can you please explain little more about " >> should be represented as a separate level." >> at present, i have put the hwid of a cpu. > > From what I undertand, the hwid of the CPU contains the "cluster" number in > this bit position, so you typically have a shared L2 or L3 cache between > all cores within a cluster, but separate caches in other clusters. > > If this is the case, there will be a measurable difference in performance > between two processes sharing memory when running on the same cluster, > or when running on different clusters on the same socket. If the > performance difference is relevant, it should be described as a separate > level in the associativity property. you mean, the associativity as array of <board> <socket> <cluster> > > Arnd thanks ganapat -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
