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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 11:46:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 11:46:25 -0700
commitb6daa51b9a6a02a644dcf6b880fd50c1f70ec07f (patch)
tree745ebeefb8f4225460774ef0037ca2f9022d4a4a /mm
parentf96ed2612260a8a415512eed4fe3f5c77247d4a1 (diff)
parent9b7396624a7b503220d85428654634b60762f2b0 (diff)
downloadlwn-b6daa51b9a6a02a644dcf6b880fd50c1f70ec07f.tar.gz
lwn-b6daa51b9a6a02a644dcf6b880fd50c1f70ec07f.zip
Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo: - Nick improved generic implementations of percpu operations which modify the variable and return so that they calculate the physical address only once. - percpu_ref percpu <-> atomic mode switching improvements. The patchset was originally posted about a year ago but fell through the crack. - misc non-critical fixes. * 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: mm/percpu.c: fix potential memory leakage for pcpu_embed_first_chunk() mm/percpu.c: correct max_distance calculation for pcpu_embed_first_chunk() percpu: eliminate two sparse warnings percpu: improve generic percpu modify-return implementation percpu-refcount: init ->confirm_switch member properly percpu_ref: allow operation mode switching operations to be called concurrently percpu_ref: restructure operation mode switching percpu_ref: unify staggered atomic switching wait behavior percpu_ref: reorganize __percpu_ref_switch_to_atomic() and relocate percpu_ref_switch_to_atomic() percpu_ref: remove unnecessary RCU grace period for staggered atomic switching confirmation
Diffstat (limited to 'mm')
-rw-r--r--mm/percpu.c38
1 files changed, 20 insertions, 18 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index 9903830aaebb..255714302394 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1961,8 +1961,9 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
void *base = (void *)ULONG_MAX;
void **areas = NULL;
struct pcpu_alloc_info *ai;
- size_t size_sum, areas_size, max_distance;
- int group, i, rc;
+ size_t size_sum, areas_size;
+ unsigned long max_distance;
+ int group, i, highest_group, rc;
ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
cpu_distance_fn);
@@ -1978,7 +1979,8 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
goto out_free;
}
- /* allocate, copy and determine base address */
+ /* allocate, copy and determine base address & max_distance */
+ highest_group = 0;
for (group = 0; group < ai->nr_groups; group++) {
struct pcpu_group_info *gi = &ai->groups[group];
unsigned int cpu = NR_CPUS;
@@ -1999,6 +2001,21 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
areas[group] = ptr;
base = min(ptr, base);
+ if (ptr > areas[highest_group])
+ highest_group = group;
+ }
+ max_distance = areas[highest_group] - base;
+ max_distance += ai->unit_size * ai->groups[highest_group].nr_units;
+
+ /* warn if maximum distance is further than 75% of vmalloc space */
+ if (max_distance > VMALLOC_TOTAL * 3 / 4) {
+ pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n",
+ max_distance, VMALLOC_TOTAL);
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+ /* and fail if we have fallback */
+ rc = -EINVAL;
+ goto out_free_areas;
+#endif
}
/*
@@ -2023,23 +2040,8 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
}
/* base address is now known, determine group base offsets */
- max_distance = 0;
for (group = 0; group < ai->nr_groups; group++) {
ai->groups[group].base_offset = areas[group] - base;
- max_distance = max_t(size_t, max_distance,
- ai->groups[group].base_offset);
- }
- max_distance += ai->unit_size;
-
- /* warn if maximum distance is further than 75% of vmalloc space */
- if (max_distance > VMALLOC_TOTAL * 3 / 4) {
- pr_warn("max_distance=0x%zx too large for vmalloc space 0x%lx\n",
- max_distance, VMALLOC_TOTAL);
-#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
- /* and fail if we have fallback */
- rc = -EINVAL;
- goto out_free;
-#endif
}
pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",