The patch titled
Subject: cacheinfo: calculate per-CPU data cache size
has been added to the -mm mm-unstable branch. Its filename is
cacheinfo-calculate-per-cpu-data-cache-size.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/cacheinfo-calculate-per-cpu-data-cache-size.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: cacheinfo: calculate per-CPU data cache size
Date: Tue, 26 Sep 2023 14:09:03 +0800
Per-CPU data cache size is useful information. For example, it can be
used to determine per-CPU cache size. So, in this patch, the data cache
size for each CPU is calculated via data_cache_size / shared_cpu_weight.
A brute-force algorithm to iterate all online CPUs is used to avoid to
allocate an extra cpumask, especially in offline callback.
Link: https://lkml.kernel.org/r/20230926060911.266511-3-ying.huang@xxxxxxxxx
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/cacheinfo.c | 42 +++++++++++++++++++++++++++++++++++-
include/linux/cacheinfo.h | 1
2 files changed, 42 insertions(+), 1 deletion(-)
--- a/drivers/base/cacheinfo.c~cacheinfo-calculate-per-cpu-data-cache-size
+++ a/drivers/base/cacheinfo.c
@@ -898,6 +898,41 @@ err:
return rc;
}
+static void update_data_cache_size_cpu(unsigned int cpu)
+{
+ struct cpu_cacheinfo *ci;
+ struct cacheinfo *leaf;
+ unsigned int i, nr_shared;
+ unsigned int size_data = 0;
+
+ if (!per_cpu_cacheinfo(cpu))
+ return;
+
+ ci = ci_cacheinfo(cpu);
+ for (i = 0; i < cache_leaves(cpu); i++) {
+ leaf = per_cpu_cacheinfo_idx(cpu, i);
+ if (leaf->type != CACHE_TYPE_DATA &&
+ leaf->type != CACHE_TYPE_UNIFIED)
+ continue;
+ nr_shared = cpumask_weight(&leaf->shared_cpu_map);
+ if (!nr_shared)
+ continue;
+ size_data += leaf->size / nr_shared;
+ }
+ ci->size_data = size_data;
+}
+
+static void update_data_cache_size(bool cpu_online, unsigned int cpu)
+{
+ unsigned int icpu;
+
+ for_each_online_cpu(icpu) {
+ if (!cpu_online && icpu == cpu)
+ continue;
+ update_data_cache_size_cpu(icpu);
+ }
+}
+
static int cacheinfo_cpu_online(unsigned int cpu)
{
int rc = detect_cache_attributes(cpu);
@@ -906,7 +941,11 @@ static int cacheinfo_cpu_online(unsigned
return rc;
rc = cache_add_dev(cpu);
if (rc)
- free_cache_attributes(cpu);
+ goto err;
+ update_data_cache_size(true, cpu);
+ return 0;
+err:
+ free_cache_attributes(cpu);
return rc;
}
@@ -916,6 +955,7 @@ static int cacheinfo_cpu_pre_down(unsign
cpu_cache_sysfs_exit(cpu);
free_cache_attributes(cpu);
+ update_data_cache_size(false, cpu);
return 0;
}
--- a/include/linux/cacheinfo.h~cacheinfo-calculate-per-cpu-data-cache-size
+++ a/include/linux/cacheinfo.h
@@ -73,6 +73,7 @@ struct cacheinfo {
struct cpu_cacheinfo {
struct cacheinfo *info_list;
+ unsigned int size_data;
unsigned int num_levels;
unsigned int num_leaves;
bool cpu_map_populated;
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
mm-fix-draining-remote-pageset.patch
memory-tiering-add-abstract-distance-calculation-algorithms-management.patch
acpi-hmat-refactor-hmat_register_target_initiators.patch
acpi-hmat-calculate-abstract-distance-with-hmat.patch
dax-kmem-calculate-abstract-distance-with-general-interface.patch
mm-pcp-avoid-to-drain-pcp-when-process-exit.patch
cacheinfo-calculate-per-cpu-data-cache-size.patch
mm-pcp-reduce-lock-contention-for-draining-high-order-pages.patch
mm-restrict-the-pcp-batch-scale-factor-to-avoid-too-long-latency.patch
mm-page_alloc-scale-the-number-of-pages-that-are-batch-allocated.patch
mm-add-framework-for-pcp-high-auto-tuning.patch
mm-tune-pcp-high-automatically.patch
mm-pcp-decrease-pcp-high-if-free-pages-high-watermark.patch
mm-pcp-avoid-to-reduce-pcp-high-unnecessarily.patch
mm-pcp-reduce-detecting-time-of-consecutive-high-order-page-freeing.patch
