Commit 0f14599c authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
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vmalloc: convert to XArray 



The radix tree of vmap blocks is simpler to express as an XArray.  Reduces
both the text and data sizes of the object file and eliminates a user of
the radix tree preload API.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200603171448.5894-1-willy@infradead.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c89ab04f

mm/vmalloc.c

+11 −29
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
#include <linux/list.h>

#include <linux/notifier.h>

#include <linux/rbtree.h>

#include <linux/radix-tree.h>

#include <linux/xarray.h>

#include <linux/rcupdate.h>

#include <linux/pfn.h>

#include <linux/kmemleak.h>
@@ -1514,12 +1514,11 @@ struct vmap_block { 
static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);



/*

 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block

 * XArray of vmap blocks, indexed by address, to quickly find a vmap block

 * in the free path. Could get rid of this if we change the API to return a

 * "cookie" from alloc, to be passed to free. But no big deal yet.

 */

static DEFINE_SPINLOCK(vmap_block_tree_lock);

static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);

static DEFINE_XARRAY(vmap_blocks);



/*

 * We should probably have a fallback mechanism to allocate virtual memory
@@ -1576,13 +1575,6 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) 
		return ERR_CAST(va);

	}



	err = radix_tree_preload(gfp_mask);

	if (unlikely(err)) {

		kfree(vb);

		free_vmap_area(va);

		return ERR_PTR(err);

	}



	vaddr = vmap_block_vaddr(va->va_start, 0);

	spin_lock_init(&vb->lock);

	vb->va = va;
@@ -1595,11 +1587,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) 
	INIT_LIST_HEAD(&vb->free_list);



	vb_idx = addr_to_vb_idx(va->va_start);

	spin_lock(&vmap_block_tree_lock);

	err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);

	spin_unlock(&vmap_block_tree_lock);

	BUG_ON(err);

	radix_tree_preload_end();

	err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask);

	if (err) {

		kfree(vb);

		free_vmap_area(va);

		return ERR_PTR(err);

	}



	vbq = &get_cpu_var(vmap_block_queue);

	spin_lock(&vbq->lock);
@@ -1613,12 +1606,8 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) 
static void free_vmap_block(struct vmap_block *vb)

{

	struct vmap_block *tmp;

	unsigned long vb_idx;



	vb_idx = addr_to_vb_idx(vb->va->va_start);

	spin_lock(&vmap_block_tree_lock);

	tmp = radix_tree_delete(&vmap_block_tree, vb_idx);

	spin_unlock(&vmap_block_tree_lock);

	tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));

	BUG_ON(tmp != vb);



	free_vmap_area_noflush(vb->va);
@@ -1724,7 +1713,6 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 
static void vb_free(unsigned long addr, unsigned long size)

{

	unsigned long offset;

	unsigned long vb_idx;

	unsigned int order;

	struct vmap_block *vb;
@@ -1734,14 +1722,8 @@ static void vb_free(unsigned long addr, unsigned long size) 
	flush_cache_vunmap(addr, addr + size);



	order = get_order(size);



	offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;



	vb_idx = addr_to_vb_idx(addr);

	rcu_read_lock();

	vb = radix_tree_lookup(&vmap_block_tree, vb_idx);

	rcu_read_unlock();

	BUG_ON(!vb);

	vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));



	unmap_kernel_range_noflush(addr, size);