-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------
This reverts commit 264266e6897dd81c894d1c5cbd90b133707b32f3.
The backport had dependencies on other mm/percpu.c restructurings,
like those in commit 020ec6537aa65c18e9084c568d7b94727f2026fd
("percpu: factor out pcpu_addr_in_first/reserved_chunk() and update
per_cpu_ptr_to_phys()"). Rather than drag in more changes, we simply
revert the incomplete backport.
Reported-by: George G. Davis <george_davis@xxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
mm/percpu.c | 46 ++++++++++++++++++++--------------------------
1 file changed, 20 insertions(+), 26 deletions(-)
diff --git a/mm/percpu.c b/mm/percpu.c
index 83523d9a351b..558543b33b52 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -111,9 +111,9 @@ static int pcpu_atom_size __read_mostly;
static int pcpu_nr_slots __read_mostly;
static size_t pcpu_chunk_struct_size __read_mostly;
-/* cpus with the lowest and highest unit addresses */
-static unsigned int pcpu_low_unit_cpu __read_mostly;
-static unsigned int pcpu_high_unit_cpu __read_mostly;
+/* cpus with the lowest and highest unit numbers */
+static unsigned int pcpu_first_unit_cpu __read_mostly;
+static unsigned int pcpu_last_unit_cpu __read_mostly;
/* the address of the first chunk which starts with the kernel static area */
void *pcpu_base_addr __read_mostly;
@@ -747,8 +747,8 @@ static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk,
int page_start, int page_end)
{
flush_cache_vunmap(
- pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
- pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+ pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
}
static void __pcpu_unmap_pages(unsigned long addr, int nr_pages)
@@ -810,8 +810,8 @@ static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk,
int page_start, int page_end)
{
flush_tlb_kernel_range(
- pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
- pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+ pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
}
static int __pcpu_map_pages(unsigned long addr, struct page **pages,
@@ -888,8 +888,8 @@ static void pcpu_post_map_flush(struct pcpu_chunk *chunk,
int page_start, int page_end)
{
flush_cache_vmap(
- pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
- pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+ pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
}
/**
@@ -1345,19 +1345,19 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
{
void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
bool in_first_chunk = false;
- unsigned long first_low, first_high;
+ unsigned long first_start, first_end;
unsigned int cpu;
/*
- * The following test on unit_low/high isn't strictly
+ * The following test on first_start/end isn't strictly
* necessary but will speed up lookups of addresses which
* aren't in the first chunk.
*/
- first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0);
- first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu,
- pcpu_unit_pages);
- if ((unsigned long)addr >= first_low &&
- (unsigned long)addr < first_high) {
+ first_start = pcpu_chunk_addr(pcpu_first_chunk, pcpu_first_unit_cpu, 0);
+ first_end = pcpu_chunk_addr(pcpu_first_chunk, pcpu_last_unit_cpu,
+ pcpu_unit_pages);
+ if ((unsigned long)addr >= first_start &&
+ (unsigned long)addr < first_end) {
for_each_possible_cpu(cpu) {
void *start = per_cpu_ptr(base, cpu);
@@ -1754,9 +1754,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
unit_map[cpu] = UINT_MAX;
-
- pcpu_low_unit_cpu = NR_CPUS;
- pcpu_high_unit_cpu = NR_CPUS;
+ pcpu_first_unit_cpu = NR_CPUS;
for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
const struct pcpu_group_info *gi = &ai->groups[group];
@@ -1776,13 +1774,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
unit_map[cpu] = unit + i;
unit_off[cpu] = gi->base_offset + i * ai->unit_size;
- /* determine low/high unit_cpu */
- if (pcpu_low_unit_cpu == NR_CPUS ||
- unit_off[cpu] < unit_off[pcpu_low_unit_cpu])
- pcpu_low_unit_cpu = cpu;
- if (pcpu_high_unit_cpu == NR_CPUS ||
- unit_off[cpu] > unit_off[pcpu_high_unit_cpu])
- pcpu_high_unit_cpu = cpu;
+ if (pcpu_first_unit_cpu == NR_CPUS)
+ pcpu_first_unit_cpu = cpu;
+ pcpu_last_unit_cpu = cpu;
}
}
pcpu_nr_units = unit;
--
1.8.5.2
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