On Fri, 24 Jul 2020 12:01:57 +0100 Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > On Wed, 8 Jul 2020 19:38:25 +0800 > Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > Unfortunately we are currently calling numa_alloc_distance well before we call > > setup_node_to_cpu_mask_map means that nr_node_ids is set to MAX_NUMNODES. > > This wastes a bit of memory and is confusing to the reader. > > > > Note we could just decide to hardcode it as MAX_NUMNODES but if so we should > > do so explicitly. > > > > Looking at what x86 does, they do a walk of nodes_parsed and locally > > establish the maximum node count seen. We can't actually do that where we > > were previously calling it in numa_init because nodes_parsed isn't set up > > either yet. So let us take a leaf entirely out of x86's book and make > > the true assumption that nodes_parsed will definitely be set up before > > we try to put a real value in this array. Hence just do it on demand. > > > > In order to avoid trying and failing to allocate the array multiple times > > we do the same thing as x86 and set numa_distance = 1. This requires a > > few small modifications elsewhere. > > > > Worth noting, that with one exception (which it appears can be removed [1]) > > the x86 and arm numa distance code is now identical. Worth factoring it > > out to some common location? > > > > [1] https://lkml.kernel.org/r/20170406124459.dwn5zhpr2xqg3lqm@xxxxxxxxxxxxxxxxxx > > > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > Polite nudge. Anyone? No particular urgency on this one but I'm thinking > of taking a stab at factoring out this code into a common location for arm64 > and x86 and this change needs to proceed that. This still applies cleanly post merge window, so still looking for some review! Jonathan > > Thanks, > > Jonathan > > > > --- > > arch/arm64/mm/numa.c | 35 ++++++++++++++++++----------------- > > 1 file changed, 18 insertions(+), 17 deletions(-) > > > > diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c > > index aafcee3e3f7e..a2f549ef0a36 100644 > > --- a/arch/arm64/mm/numa.c > > +++ b/arch/arm64/mm/numa.c > > @@ -255,13 +255,11 @@ void __init numa_free_distance(void) > > { > > size_t size; > > > > - if (!numa_distance) > > - return; > > - > > size = numa_distance_cnt * numa_distance_cnt * > > sizeof(numa_distance[0]); > > - > > - memblock_free(__pa(numa_distance), size); > > + /* numa_distance could be 1LU marking allocation failure, test cnt */ > > + if (numa_distance_cnt) > > + memblock_free(__pa(numa_distance), size); > > numa_distance_cnt = 0; > > numa_distance = NULL; > > } > > @@ -271,20 +269,29 @@ void __init numa_free_distance(void) > > */ > > static int __init numa_alloc_distance(void) > > { > > + nodemask_t nodes_parsed; > > size_t size; > > + int i, j, cnt = 0; > > u64 phys; > > - int i, j; > > > > - size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]); > > + /* size the new table and allocate it */ > > + nodes_parsed = numa_nodes_parsed; > > + for_each_node_mask(i, nodes_parsed) > > + cnt = i; > > + cnt++; > > + size = cnt * cnt * sizeof(numa_distance[0]); > > phys = memblock_find_in_range(0, PFN_PHYS(max_pfn), > > size, PAGE_SIZE); > > - if (WARN_ON(!phys)) > > + if (!phys) { > > + pr_warn("Warning: can't allocate distance table!\n"); > > + /* don't retry until explicitly reset */ > > + numa_distance = (void *)1LU; > > return -ENOMEM; > > - > > + } > > memblock_reserve(phys, size); > > > > numa_distance = __va(phys); > > - numa_distance_cnt = nr_node_ids; > > + numa_distance_cnt = cnt; > > > > /* fill with the default distances */ > > for (i = 0; i < numa_distance_cnt; i++) > > @@ -311,10 +318,8 @@ static int __init numa_alloc_distance(void) > > */ > > void __init numa_set_distance(int from, int to, int distance) > > { > > - if (!numa_distance) { > > - pr_warn_once("Warning: distance table not allocated yet\n"); > > + if (!numa_distance && numa_alloc_distance() < 0) > > return; > > - } > > > > if (from >= numa_distance_cnt || to >= numa_distance_cnt || > > from < 0 || to < 0) { > > @@ -384,10 +389,6 @@ static int __init numa_init(int (*init_func)(void)) > > nodes_clear(node_possible_map); > > nodes_clear(node_online_map); > > > > - ret = numa_alloc_distance(); > > - if (ret < 0) > > - return ret; > > - > > ret = init_func(); > > if (ret < 0) > > goto out_free_distance; > > > _______________________________________________ > Linuxarm mailing list > Linuxarm@xxxxxxxxxx > http://hulk.huawei.com/mailman/listinfo/linuxarm
