diff options
| author | Michael Ellerman <mpe@ellerman.id.au> | 2023-07-05 16:51:37 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2023-07-28 09:53:37 +0200 |
| commit | 447ae4ac41130a7f127c2581a5e816bb0800b560 (patch) | |
| tree | 04bf32880c7259d4eaecc8f9ff0f8da59b6c6d98 /include/linux/cpu_smt.h | |
| parent | c53361ce7d8771129c517dca529d2f2dc5bf04d1 (diff) | |
cpu/SMT: Store the current/max number of threads
Some architectures allow partial SMT states at boot time, ie. when not all
SMT threads are brought online.
To support that the SMT code needs to know the maximum number of SMT
threads, and also the currently configured number.
The architecture code knows the max number of threads, so have the
architecture code pass that value to cpu_smt_set_num_threads(). Note that
although topology_max_smt_threads() exists, it is not configured early
enough to be used here. As architecture, like PowerPC, allows the threads
number to be set through the kernel command line, also pass that value.
[ ldufour: Slightly reword the commit message ]
[ ldufour: Rename cpu_smt_check_topology and add a num_threads argument ]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20230705145143.40545-5-ldufour@linux.ibm.com
Diffstat (limited to 'include/linux/cpu_smt.h')
| -rw-r--r-- | include/linux/cpu_smt.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/cpu_smt.h b/include/linux/cpu_smt.h index 722c2e306fef..0c1664294b57 100644 --- a/include/linux/cpu_smt.h +++ b/include/linux/cpu_smt.h @@ -12,15 +12,19 @@ enum cpuhp_smt_control { #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) extern enum cpuhp_smt_control cpu_smt_control; +extern unsigned int cpu_smt_num_threads; extern void cpu_smt_disable(bool force); -extern void cpu_smt_check_topology(void); +extern void cpu_smt_set_num_threads(unsigned int num_threads, + unsigned int max_threads); extern bool cpu_smt_possible(void); extern int cpuhp_smt_enable(void); extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval); #else # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) +# define cpu_smt_num_threads 1 static inline void cpu_smt_disable(bool force) { } -static inline void cpu_smt_check_topology(void) { } +static inline void cpu_smt_set_num_threads(unsigned int num_threads, + unsigned int max_threads) { } static inline bool cpu_smt_possible(void) { return false; } static inline int cpuhp_smt_enable(void) { return 0; } static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } |