x86-64, NUMA: Fix distance table handling
NUMA distance table handling has the following problems.
* numa_reset_distance() uses numa_distance * sizeof(numa_distance[0])
as the table size when it should be using the square of
numa_distance.
* The same size miscalculation when allocation space for phys_dist in
numa_emulation().
* In numa_emulation(), phys_dist must be reserved; otherwise, the new
emulated distance table may overlap it.
Fix them and, while at it, take numa_distance_cnt resetting in
numa_reset_distance() out of the if block to simplify the code a bit.
David Rientjes reported incorrect handling of distance table during
emulation.
-tj: Edited out numa_alloc_distance() related changes which weren't
necessary and rewrote patch description.
-v2: Ingo was unhappy with 80-column limit induced linebreaks. Let
lines run over 80-column.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: David Rientjes <rientjes@google.com>
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index 607a2e8..0afa25d 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -300,6 +300,7 @@
static struct numa_meminfo pi __initdata;
const u64 max_addr = max_pfn << PAGE_SHIFT;
u8 *phys_dist = NULL;
+ size_t phys_size = numa_dist_cnt * numa_dist_cnt * sizeof(phys_dist[0]);
int i, j, ret;
if (!emu_cmdline)
@@ -336,21 +337,18 @@
goto no_emu;
}
- /*
- * Copy the original distance table. It's temporary so no need to
- * reserve it.
- */
+ /* copy the physical distance table */
if (numa_dist_cnt) {
- size_t size = numa_dist_cnt * sizeof(phys_dist[0]);
u64 phys;
phys = memblock_find_in_range(0,
(u64)max_pfn_mapped << PAGE_SHIFT,
- size, PAGE_SIZE);
+ phys_size, PAGE_SIZE);
if (phys == MEMBLOCK_ERROR) {
pr_warning("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");
goto no_emu;
}
+ memblock_x86_reserve_range(phys, phys + phys_size, "TMP NUMA DIST");
phys_dist = __va(phys);
for (i = 0; i < numa_dist_cnt; i++)
@@ -398,6 +396,10 @@
numa_set_distance(i, j, dist);
}
}
+
+ /* free the copied physical distance table */
+ if (phys_dist)
+ memblock_x86_free_range(__pa(phys_dist), __pa(phys_dist) + phys_size);
return;
no_emu: