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| author | Chen Yu <yu.c.chen@intel.com> | 2026-05-13 13:39:15 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-05-18 21:33:15 +0200 |
| commit | 7030513a08776b2ca70fccd5dfddf7bb5c5c88ba (patch) | |
| tree | b6ac0c9c88403aac76c35ac15db4e5913f08400b /include | |
| parent | 7b34bb1ca324451c84c0a69136ce92e7928cf72b (diff) | |
| download | lwn-7030513a08776b2ca70fccd5dfddf7bb5c5c88ba.tar.gz lwn-7030513a08776b2ca70fccd5dfddf7bb5c5c88ba.zip | |
sched/cache: Calculate the LLC size and store it in sched_domain
Cache aware scheduling needs to know the LLC size that a process
can use, so as to avoid memory-intensive tasks from being
over-aggregated on a single LLC.
Introduce a preparation patch to add get_effective_llc_bytes() to
get the LLC size that a CPU can use. The function can be further
enhanced by subtracting the LLC cache ways reserved by resctrl
(CAT in Intel RDT, etc).
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/37afee09ff608034da0ce149e72d33b6f4698edf.1778703694.git.tim.c.chen@linux.intel.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cacheinfo.h | 1 | ||||
| -rw-r--r-- | include/linux/sched/topology.h | 7 |
2 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h index c8f4f0a0b874..fc879ac4cc4f 100644 --- a/include/linux/cacheinfo.h +++ b/include/linux/cacheinfo.h @@ -89,6 +89,7 @@ int populate_cache_leaves(unsigned int cpu); int cache_setup_acpi(unsigned int cpu); bool last_level_cache_is_valid(unsigned int cpu); bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y); +struct cacheinfo *get_cpu_cacheinfo_llc(unsigned int cpu); int fetch_cache_info(unsigned int cpu); int detect_cache_attributes(unsigned int cpu); #ifndef CONFIG_ACPI_PPTT diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 0036d6b4bd67..fe09d3268bc9 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -106,6 +106,7 @@ struct sched_domain { #ifdef CONFIG_SCHED_CACHE unsigned int llc_max; unsigned int *llc_counts __counted_by_ptr(llc_max); + unsigned long llc_bytes; #endif #ifdef CONFIG_SCHEDSTATS @@ -265,4 +266,10 @@ static inline int task_node(const struct task_struct *p) return cpu_to_node(task_cpu(p)); } +#ifdef CONFIG_SCHED_CACHE +extern void sched_update_llc_bytes(unsigned int cpu); +#else +static inline void sched_update_llc_bytes(unsigned int cpu) { } +#endif + #endif /* _LINUX_SCHED_TOPOLOGY_H */ |