Messages in this thread | | | From | "Song Bao Hua (Barry Song)" <> | Subject | RE: [RFC PATCH v5 1/4] topology: Represent clusters of CPUs within a die | Date | Fri, 19 Mar 2021 06:57:08 +0000 |
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> -----Original Message----- > From: Greg KH [mailto:gregkh@linuxfoundation.org] > Sent: Friday, March 19, 2021 7:35 PM > To: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com> > Cc: tim.c.chen@linux.intel.com; catalin.marinas@arm.com; will@kernel.org; > rjw@rjwysocki.net; vincent.guittot@linaro.org; bp@alien8.de; > tglx@linutronix.de; mingo@redhat.com; lenb@kernel.org; peterz@infradead.org; > dietmar.eggemann@arm.com; rostedt@goodmis.org; bsegall@google.com; > mgorman@suse.de; msys.mizuma@gmail.com; valentin.schneider@arm.com; Jonathan > Cameron <jonathan.cameron@huawei.com>; juri.lelli@redhat.com; > mark.rutland@arm.com; sudeep.holla@arm.com; aubrey.li@linux.intel.com; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; > linux-acpi@vger.kernel.org; x86@kernel.org; xuwei (O) <xuwei5@huawei.com>; > Zengtao (B) <prime.zeng@hisilicon.com>; guodong.xu@linaro.org; yangyicong > <yangyicong@huawei.com>; Liguozhu (Kenneth) <liguozhu@hisilicon.com>; > linuxarm@openeuler.org; hpa@zytor.com > Subject: Re: [RFC PATCH v5 1/4] topology: Represent clusters of CPUs within > a die > > On Fri, Mar 19, 2021 at 05:16:15PM +1300, Barry Song wrote: > > diff --git a/Documentation/admin-guide/cputopology.rst > b/Documentation/admin-guide/cputopology.rst > > index b90dafc..f9d3745 100644 > > --- a/Documentation/admin-guide/cputopology.rst > > +++ b/Documentation/admin-guide/cputopology.rst > > @@ -24,6 +24,12 @@ core_id: > > identifier (rather than the kernel's). The actual value is > > architecture and platform dependent. > > > > +cluster_id: > > + > > + the Cluster ID of cpuX. Typically it is the hardware platform's > > + identifier (rather than the kernel's). The actual value is > > + architecture and platform dependent. > > + > > book_id: > > > > the book ID of cpuX. Typically it is the hardware platform's > > @@ -56,6 +62,14 @@ package_cpus_list: > > human-readable list of CPUs sharing the same physical_package_id. > > (deprecated name: "core_siblings_list") > > > > +cluster_cpus: > > + > > + internal kernel map of CPUs within the same cluster. > > + > > +cluster_cpus_list: > > + > > + human-readable list of CPUs within the same cluster. > > + > > die_cpus: > > > > internal kernel map of CPUs within the same die. > > Why are these sysfs files in this file, and not in a Documentation/ABI/ > file which can be correctly parsed and shown to userspace?
Well. Those ABIs have been there for much a long time. It is like:
[root@ceph1 topology]# ls core_id core_siblings core_siblings_list physical_package_id thread_siblings thread_siblings_list [root@ceph1 topology]# pwd /sys/devices/system/cpu/cpu100/topology [root@ceph1 topology]# cat core_siblings_list 64-127 [root@ceph1 topology]#
> > Any chance you can fix that up here as well?
Yes. we will send a separate patch to address this, which won't be in this patchset. This patchset will base on that one.
> > Also note that "list" is not something that goes in sysfs, sysfs is "one > value per file", and a list is not "one value". How do you prevent > overflowing the buffer of the sysfs file if you have a "list"? >
At a glance, the list is using "-" rather than a real list [root@ceph1 topology]# cat core_siblings_list 64-127
Anyway, I will take a look if it has any chance to overflow.
> thanks, > > greg k-h
Thanks Barry
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