[PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()
From: Roman Gushchin <hidden>
Date: 2018-12-19 17:38:09
Also in:
lkml
Subsystem:
memory management, the rest, vmalloc · Maintainers:
Andrew Morton, Linus Torvalds, Uladzislau Rezki
alloc_vmap_area() is allocating memory for the vmap_area, and performing the actual lookup of the vm area and vmap_area initialization. This prevents us from using a pre-allocated memory for the map_area structure, which can be used in some cases to minimize the number of required memory allocations. Let's keep the memory allocation part in alloc_vmap_area() and separate everything else into init_vmap_area(). Signed-off-by: Roman Gushchin <redacted> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Matthew Wilcox <willy@infradead.org> --- mm/vmalloc.c | 50 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 17 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 7660e3ef4133..042175d7d95f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c@@ -395,16 +395,10 @@ static void purge_vmap_area_lazy(void); static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); -/* - * Allocate a region of KVA of the specified size and alignment, within the - * vstart and vend. - */ -static struct vmap_area *alloc_vmap_area(unsigned long size, - unsigned long align, - unsigned long vstart, unsigned long vend, - int node, gfp_t gfp_mask) +static int init_vmap_area(struct vmap_area *va, unsigned long size, + unsigned long align, unsigned long vstart, + unsigned long vend, int node, gfp_t gfp_mask) { - struct vmap_area *va; struct rb_node *n; unsigned long addr; int purged = 0;
@@ -416,11 +410,6 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, might_sleep(); - va = kmalloc_node(sizeof(struct vmap_area), - gfp_mask & GFP_RECLAIM_MASK, node); - if (unlikely(!va)) - return ERR_PTR(-ENOMEM); - /* * Only scan the relevant parts containing pointers to other objects * to avoid false negatives.
@@ -512,7 +501,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, BUG_ON(va->va_start < vstart); BUG_ON(va->va_end > vend); - return va; + return 0; overflow: spin_unlock(&vmap_area_lock);
@@ -534,8 +523,35 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", size); - kfree(va); - return ERR_PTR(-EBUSY); + + return -EBUSY; +} + +/* + * Allocate a region of KVA of the specified size and alignment, within the + * vstart and vend. + */ +static struct vmap_area *alloc_vmap_area(unsigned long size, + unsigned long align, + unsigned long vstart, + unsigned long vend, + int node, gfp_t gfp_mask) +{ + struct vmap_area *va; + int ret; + + va = kmalloc_node(sizeof(struct vmap_area), + gfp_mask & GFP_RECLAIM_MASK, node); + if (unlikely(!va)) + return ERR_PTR(-ENOMEM); + + ret = init_vmap_area(va, size, align, vstart, vend, node, gfp_mask); + if (ret) { + kfree(va); + return ERR_PTR(ret); + } + + return va; } int register_vmap_purge_notifier(struct notifier_block *nb)
--
2.19.2