linux_dsm_epyc7002/arch/x86/include/asm/resctrl_sched.h
Johannes Weiner e6d429313e x86/resctrl: Avoid confusion over the new X86_RESCTRL config
"Resource Control" is a very broad term for this CPU feature, and a term
that is also associated with containers, cgroups etc. This can easily
cause confusion.

Make the user prompt more specific. Match the config symbol name.

 [ bp: In the future, the corresponding ARM arch-specific code will be
   under ARM_CPU_RESCTRL and the arch-agnostic bits will be carved out
   under the CPU_RESCTRL umbrella symbol. ]

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190130195621.GA30653@cmpxchg.org
2019-02-02 10:34:52 +01:00

94 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_RESCTRL_SCHED_H
#define _ASM_X86_RESCTRL_SCHED_H
#ifdef CONFIG_X86_CPU_RESCTRL
#include <linux/sched.h>
#include <linux/jump_label.h>
#define IA32_PQR_ASSOC 0x0c8f
/**
* struct resctrl_pqr_state - State cache for the PQR MSR
* @cur_rmid: The cached Resource Monitoring ID
* @cur_closid: The cached Class Of Service ID
* @default_rmid: The user assigned Resource Monitoring ID
* @default_closid: The user assigned cached Class Of Service ID
*
* The upper 32 bits of IA32_PQR_ASSOC contain closid and the
* lower 10 bits rmid. The update to IA32_PQR_ASSOC always
* contains both parts, so we need to cache them. This also
* stores the user configured per cpu CLOSID and RMID.
*
* The cache also helps to avoid pointless updates if the value does
* not change.
*/
struct resctrl_pqr_state {
u32 cur_rmid;
u32 cur_closid;
u32 default_rmid;
u32 default_closid;
};
DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state);
DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
/*
* __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
*
* Following considerations are made so that this has minimal impact
* on scheduler hot path:
* - This will stay as no-op unless we are running on an Intel SKU
* which supports resource control or monitoring and we enable by
* mounting the resctrl file system.
* - Caches the per cpu CLOSid/RMID values and does the MSR write only
* when a task with a different CLOSid/RMID is scheduled in.
* - We allocate RMIDs/CLOSids globally in order to keep this as
* simple as possible.
* Must be called with preemption disabled.
*/
static void __resctrl_sched_in(void)
{
struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state);
u32 closid = state->default_closid;
u32 rmid = state->default_rmid;
/*
* If this task has a closid/rmid assigned, use it.
* Else use the closid/rmid assigned to this cpu.
*/
if (static_branch_likely(&rdt_alloc_enable_key)) {
if (current->closid)
closid = current->closid;
}
if (static_branch_likely(&rdt_mon_enable_key)) {
if (current->rmid)
rmid = current->rmid;
}
if (closid != state->cur_closid || rmid != state->cur_rmid) {
state->cur_closid = closid;
state->cur_rmid = rmid;
wrmsr(IA32_PQR_ASSOC, rmid, closid);
}
}
static inline void resctrl_sched_in(void)
{
if (static_branch_likely(&rdt_enable_key))
__resctrl_sched_in();
}
#else
static inline void resctrl_sched_in(void) {}
#endif /* CONFIG_X86_CPU_RESCTRL */
#endif /* _ASM_X86_RESCTRL_SCHED_H */