From: Chen Wandun <chenwandun@xxxxxxxxxx> Subject: mm/vmalloc: introduce alloc_pages_bulk_array_mempolicy to accelerate memory allocation "mm/vmalloc: fix numa spreading for large hash tables" will cause significant performance regressions in some situations as Andrew mentioned in [1]. The main situation is vmalloc, vmalloc will allocate pages with NUMA_NO_NODE by default, that will result in alloc page one by one; In order to solve this, __alloc_pages_bulk and mempolicy should be considered at the same time. 1) If node is specified in memory allocation request, it will alloc all pages by __alloc_pages_bulk. 2) If interleaving allocate memory, it will cauculate how many pages should be allocated in each node, and use __alloc_pages_bulk to alloc pages in each node. [1]: https://lore.kernel.org/lkml/CALvZod4G3SzP3kWxQYn0fj+VgG-G3yWXz=gz17+3N57ru1iajw@xxxxxxxxxxxxxx/t/#m750c8e3231206134293b089feaa090590afa0f60 [akpm@xxxxxxxxxxxxxxxxxxxx: coding style fixes] [akpm@xxxxxxxxxxxxxxxxxxxx: make two functions static] [akpm@xxxxxxxxxxxxxxxxxxxx: fix CONFIG_NUMA=n build] Link: https://lkml.kernel.org/r/20211021080744.874701-3-chenwandun@xxxxxxxxxx Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx> Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Hanjun Guo <guohanjun@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/gfp.h | 4 ++ mm/mempolicy.c | 82 ++++++++++++++++++++++++++++++++++++++++++ mm/vmalloc.c | 20 ++++++++-- 3 files changed, 102 insertions(+), 4 deletions(-) --- a/include/linux/gfp.h~mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation +++ a/include/linux/gfp.h @@ -535,6 +535,10 @@ unsigned long __alloc_pages_bulk(gfp_t g struct list_head *page_list, struct page **page_array); +unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp, + unsigned long nr_pages, + struct page **page_array); + /* Bulk allocate order-0 pages */ static inline unsigned long alloc_pages_bulk_list(gfp_t gfp, unsigned long nr_pages, struct list_head *list) --- a/mm/mempolicy.c~mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation +++ a/mm/mempolicy.c @@ -2196,6 +2196,88 @@ struct page *alloc_pages(gfp_t gfp, unsi } EXPORT_SYMBOL(alloc_pages); +static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp, + struct mempolicy *pol, unsigned long nr_pages, + struct page **page_array) +{ + int nodes; + unsigned long nr_pages_per_node; + int delta; + int i; + unsigned long nr_allocated; + unsigned long total_allocated = 0; + + nodes = nodes_weight(pol->nodes); + nr_pages_per_node = nr_pages / nodes; + delta = nr_pages - nodes * nr_pages_per_node; + + for (i = 0; i < nodes; i++) { + if (delta) { + nr_allocated = __alloc_pages_bulk(gfp, + interleave_nodes(pol), NULL, + nr_pages_per_node + 1, NULL, + page_array); + delta--; + } else { + nr_allocated = __alloc_pages_bulk(gfp, + interleave_nodes(pol), NULL, + nr_pages_per_node, NULL, page_array); + } + + page_array += nr_allocated; + total_allocated += nr_allocated; + } + + return total_allocated; +} + +static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid, + struct mempolicy *pol, unsigned long nr_pages, + struct page **page_array) +{ + gfp_t preferred_gfp; + unsigned long nr_allocated = 0; + + preferred_gfp = gfp | __GFP_NOWARN; + preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); + + nr_allocated = __alloc_pages_bulk(preferred_gfp, nid, &pol->nodes, + nr_pages, NULL, page_array); + + if (nr_allocated < nr_pages) + nr_allocated += __alloc_pages_bulk(gfp, numa_node_id(), NULL, + nr_pages - nr_allocated, NULL, + page_array + nr_allocated); + return nr_allocated; +} + +/* alloc pages bulk and mempolicy should be considered at the + * same time in some situation such as vmalloc. + * + * It can accelerate memory allocation especially interleaving + * allocate memory. + */ +unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp, + unsigned long nr_pages, struct page **page_array) +{ + struct mempolicy *pol = &default_policy; + + if (!in_interrupt() && !(gfp & __GFP_THISNODE)) + pol = get_task_policy(current); + + if (pol->mode == MPOL_INTERLEAVE) + return alloc_pages_bulk_array_interleave(gfp, pol, + nr_pages, page_array); + + if (pol->mode == MPOL_PREFERRED_MANY) + return alloc_pages_bulk_array_preferred_many(gfp, + numa_node_id(), pol, nr_pages, page_array); + + return __alloc_pages_bulk(gfp, policy_node(gfp, pol, numa_node_id()), + policy_nodemask(gfp, pol), nr_pages, NULL, + page_array); +} + int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) { struct mempolicy *pol = mpol_dup(vma_policy(src)); --- a/mm/vmalloc.c~mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation +++ a/mm/vmalloc.c @@ -2843,7 +2843,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * to fails, fallback to a single page allocator that is * more permissive. */ - if (!order && nid != NUMA_NO_NODE) { + if (!order) { while (nr_allocated < nr_pages) { unsigned int nr, nr_pages_request; @@ -2855,8 +2855,20 @@ vm_area_alloc_pages(gfp_t gfp, int nid, */ nr_pages_request = min(100U, nr_pages - nr_allocated); - nr = alloc_pages_bulk_array_node(gfp, nid, - nr_pages_request, pages + nr_allocated); + /* memory allocation should consider mempolicy, we can't + * wrongly use nearest node when nid == NUMA_NO_NODE, + * otherwise memory may be allocated in only one node, + * but mempolcy want to alloc memory by interleaving. + */ + if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) + nr = alloc_pages_bulk_array_mempolicy(gfp, + nr_pages_request, + pages + nr_allocated); + + else + nr = alloc_pages_bulk_array_node(gfp, nid, + nr_pages_request, + pages + nr_allocated); nr_allocated += nr; cond_resched(); @@ -2868,7 +2880,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, if (nr != nr_pages_request) break; } - } else if (order) + } else /* * Compound pages required for remap_vmalloc_page if * high-order pages. _
