mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
6909f179ca
On Pseries LPARs, to calculate utilization, we need to know the [S]PURR ticks when the CPUs were busy or idle. The total PURR and SPURR ticks are already exposed via the per-cpu sysfs files "purr" and "spurr". This patch adds support for exposing the idle PURR and SPURR ticks via new per-cpu sysfs files named "idle_purr" and "idle_spurr". This patch also adds helper functions to accurately read the values of idle_purr and idle_spurr especially from an interrupt context between when the interrupt has occurred between the pseries_idle_prolog() and pseries_idle_epilog(). This will ensure that the idle purr/spurr values corresponding to the latest idle period is accounted for before these values are read. Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1586249263-14048-5-git-send-email-ego@linux.vnet.ibm.com
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
#ifndef _ASM_POWERPC_IDLE_H
|
|
#define _ASM_POWERPC_IDLE_H
|
|
#include <asm/runlatch.h>
|
|
#include <asm/paca.h>
|
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
DECLARE_PER_CPU(u64, idle_spurr_cycles);
|
|
DECLARE_PER_CPU(u64, idle_entry_purr_snap);
|
|
DECLARE_PER_CPU(u64, idle_entry_spurr_snap);
|
|
|
|
static inline void snapshot_purr_idle_entry(void)
|
|
{
|
|
*this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR);
|
|
}
|
|
|
|
static inline void snapshot_spurr_idle_entry(void)
|
|
{
|
|
*this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR);
|
|
}
|
|
|
|
static inline void update_idle_purr_accounting(void)
|
|
{
|
|
u64 wait_cycles;
|
|
u64 in_purr = *this_cpu_ptr(&idle_entry_purr_snap);
|
|
|
|
wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
|
|
wait_cycles += mfspr(SPRN_PURR) - in_purr;
|
|
get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
|
|
}
|
|
|
|
static inline void update_idle_spurr_accounting(void)
|
|
{
|
|
u64 *idle_spurr_cycles_ptr = this_cpu_ptr(&idle_spurr_cycles);
|
|
u64 in_spurr = *this_cpu_ptr(&idle_entry_spurr_snap);
|
|
|
|
*idle_spurr_cycles_ptr += mfspr(SPRN_SPURR) - in_spurr;
|
|
}
|
|
|
|
static inline void pseries_idle_prolog(void)
|
|
{
|
|
ppc64_runlatch_off();
|
|
snapshot_purr_idle_entry();
|
|
snapshot_spurr_idle_entry();
|
|
/*
|
|
* Indicate to the HV that we are idle. Now would be
|
|
* a good time to find other work to dispatch.
|
|
*/
|
|
get_lppaca()->idle = 1;
|
|
}
|
|
|
|
static inline void pseries_idle_epilog(void)
|
|
{
|
|
update_idle_purr_accounting();
|
|
update_idle_spurr_accounting();
|
|
get_lppaca()->idle = 0;
|
|
ppc64_runlatch_on();
|
|
}
|
|
|
|
static inline u64 read_this_idle_purr(void)
|
|
{
|
|
/*
|
|
* If we are reading from an idle context, update the
|
|
* idle-purr cycles corresponding to the last idle period.
|
|
* Since the idle context is not yet over, take a fresh
|
|
* snapshot of the idle-purr.
|
|
*/
|
|
if (unlikely(get_lppaca()->idle == 1)) {
|
|
update_idle_purr_accounting();
|
|
snapshot_purr_idle_entry();
|
|
}
|
|
|
|
return be64_to_cpu(get_lppaca()->wait_state_cycles);
|
|
}
|
|
|
|
static inline u64 read_this_idle_spurr(void)
|
|
{
|
|
/*
|
|
* If we are reading from an idle context, update the
|
|
* idle-spurr cycles corresponding to the last idle period.
|
|
* Since the idle context is not yet over, take a fresh
|
|
* snapshot of the idle-spurr.
|
|
*/
|
|
if (get_lppaca()->idle == 1) {
|
|
update_idle_spurr_accounting();
|
|
snapshot_spurr_idle_entry();
|
|
}
|
|
|
|
return *this_cpu_ptr(&idle_spurr_cycles);
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_PSERIES */
|
|
#endif
|