x86/intel_rdt: Add mkdir to resctrl file system
authorFenghua Yu <fenghua.yu@intel.com>
Fri, 28 Oct 2016 22:04:44 +0000 (15:04 -0700)
committerThomas Gleixner <tglx@linutronix.de>
Mon, 31 Oct 2016 01:10:14 +0000 (19:10 -0600)
commit60cf5e101fd4441ab112a81e88726efb6fd7542c
treec1309f836c0fe980f35a1b64d22ffe2cf1ca6faf
parent4e978d06dedb8207b298a5a8a49fce4b2ab80d12
x86/intel_rdt: Add mkdir to resctrl file system

Resource control groups are represented as directories in the resctrl
file system. The root directory describes the default resources available
to tasks that have not been assigned specific resources. Other directories
can be created at the root level to make new resource groups. It is not
permitted to make directories within other directories.

Hardware uses a CLOSID (Class of service ID) to determine which resource
limits are currently in effect. The exact number available is enumerated
by CPUID leaf 0x10, but on current implementations it is a small number.
We implement a simple bitmask allocator for CLOSIDs.

Each resource control group uses one CLOSID, which limits the total number
of directories that can be created.

Resource groups can be removed using rmdir.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/include/asm/intel_rdt.h
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c