The cpu online/offline callbacks of intel_rdt lock rdtgroup_mutex nested
inside of cpu hotplug lock. rdtgroup_cpus_write() does it in reverse order.
Remove the get/put_online_cpus() calls from rdtgroup_cpus_write(). This is
safe against cpu hotplug as the resource group cpumasks are protected by
rdtgroup_mutex.
Found by review, but should have been found if authors would have bothered
to test cpu hotplug with lockdep enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Shaohua Li <shli@fb.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
The info directory and the per-resource subdirectories of the info
directory have no reference to a struct rdtgroup in kn->priv. An attempt to
remove one of those directories results in a NULL pointer dereference.
Protect the directories from removal and return -EPERM instead of -ENOENT.
[ tglx: Massaged changelog ]
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: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1478912558-55514-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
gcc complains:
"warning: ‘dentry’ may be used uninitialized in this function"
The error exit path in rdt_mount(), which deals with a failure in
rdtgroup_create_info_dir(), does not set the error code in dentry and
returns the uninitialized dentry value.
Add the missing error propagation.
[tglx: Massaged changelog ]
Fixes: 4e978d06de ("x86/intel_rdt: Add "info" files to resctrl file system")
Signed-off-by: Shaohua Li <shli@fb.com>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/a56a556f6768dc12cadbf97f49e000189056f90e.1478207143.git.shli@fb.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hook the x86 scheduler code to update closid based on whether the current
task is assigned to a specific closid or running on a CPU assigned to a
specific closid.
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/1477692289-37412-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Last of the per resource group files. Also mode 0644. This one shows
the resources available to the group. Syntax depends on whether the
"cdp" mount option was given. With code/data prioritization disabled
it is simply a list of masks for each cache domain. Initial value
allows access to all of the L3 cache on all domains. E.g. on a 2 socket
Broadwell:
L3:0=fffff;1=fffff
With CDP enabled, separate masks for data and instructions are provided:
L3DATA:0=fffff;1=fffff
L3CODE:0=fffff;1=fffff
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@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/1477692289-37412-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The root directory all subdirectories are automatically populated with a
read/write (mode 0644) file named "tasks". When read it will show all the
task IDs assigned to the resource group. Tasks can be added (one at a time)
to a group by writing the task ID to the file. E.g.
Membership in a resource group is indicated by a new field in the
task_struct "int closid" which holds the CLOSID for each task. The default
resource group uses CLOSID=0 which means that all existing tasks when the
resctrl file system is mounted belong to the default group.
If a group is removed, tasks which are members of that group are moved to
the default group.
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/1477692289-37412-8-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now we populate each directory with a read/write (mode 0644) file
named "cpus". This is used to over-ride the resources available
to processes in the default resource group when running on specific
CPUs. Each "cpus" file reads as a cpumask showing which CPUs belong
to this resource group. Initially all online CPUs are assigned to
the default group. They can be added to other groups by writing a
cpumask to the "cpus" file in the directory for the resource group
(which will remove them from the previous group to which they were
assigned). CPU online/offline operations will delete CPUs that go
offline from whatever group they are in and add new CPUs to the
default group.
If there are CPUs assigned to a group when the directory is removed,
they are returned to the default group.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@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/1477692289-37412-7-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
Use kernfs as basis for our user interface filesystem. This patch
supports mount/umount, and one mount parameter "cdp" to enable code/data
prioritization (though all we do at this point is ensure that the system
can support CDP). The file system is not populated yet in this patch.
[ tglx: Fixed up a few nits and added cdp handling in case of error ]
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/1477692289-37412-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Thomas Gleixner