diff options
| author | Tejun Heo <tj@kernel.org> | 2011-03-02 10:32:47 (GMT) |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2011-03-02 15:34:21 (GMT) |
| commit | eb8c1e2c830fc25c93bc94e215ed387fe142a98d (patch) | |
| tree | 21c87bb959e98a1639f6de575f8a630c4cb4e261 /arch/x86/mm | |
| parent | ce0033307f1b45e23e0c149f56ea4855eb4687ce (diff) | |
| download | linux-eb8c1e2c830fc25c93bc94e215ed387fe142a98d.tar.xz | |
x86-64, NUMA: Better explain numa_distance handling
Handling of out-of-bounds distances and allocation failure can use
better documentation. Add it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/numa_64.c | 11 | ||||
| -rw-r--r-- | arch/x86/mm/numa_emulation.c | 6 |
2 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index 541746f..74064e8 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -392,11 +392,12 @@ void __init numa_reset_distance(void) { size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]); + /* numa_distance could be 1LU marking allocation failure, test cnt */ if (numa_distance_cnt) memblock_x86_free_range(__pa(numa_distance), __pa(numa_distance) + size); numa_distance_cnt = 0; - numa_distance = NULL; + numa_distance = NULL; /* enable table creation */ } static int __init numa_alloc_distance(void) @@ -447,6 +448,14 @@ static int __init numa_alloc_distance(void) * Set the distance from node @from to @to to @distance. If distance table * doesn't exist, one which is large enough to accomodate all the currently * known nodes will be created. + * + * If such table cannot be allocated, a warning is printed and further + * calls are ignored until the distance table is reset with + * numa_reset_distance(). + * + * If @from or @to is higher than the highest known node at the time of + * table creation or @distance doesn't make sense, the call is ignored. + * This is to allow simplification of specific NUMA config implementations. */ void __init numa_set_distance(int from, int to, int distance) { diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index 0afa25d..aeecea9 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -379,7 +379,11 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) if (emu_nid_to_phys[i] == NUMA_NO_NODE) emu_nid_to_phys[i] = 0; - /* transform distance table */ + /* + * Transform distance table. numa_set_distance() ignores all + * out-of-bound distances. Just call it for every possible node + * combination. + */ numa_reset_distance(); for (i = 0; i < MAX_NUMNODES; i++) { for (j = 0; j < MAX_NUMNODES; j++) { |