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RDMA/odp: Use the common interval tree library instead of generic

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ODP is working with userspace VA's in the interval tree which always fit
into an unsigned long, so we can use the common code.

This comes at a cost of a 16 byte increase in ib_umem_odp struct size due
to storing the interval tree start/last in addition to the umem
addr/length. However these values were computed and are performance
critical for the interval lookup, so this seems like a worthwhile trade
off.

Removes 2k of .text from the kernel.

Link: https://lore.kernel.org/r/20190819111710.18440-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Jason Gunthorpe 2019-08-19 14:16:59 +03:00
parent 27b7fb1ab7
commit 7cc2e18f21
3 changed files with 31 additions and 62 deletions
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1
drivers/infiniband/Kconfig
View File

@ -55,6 +55,7 @@ config INFINIBAND_ON_DEMAND_PAGING
bool "InfiniBand on-demand paging support"
depends on INFINIBAND_USER_MEM
select MMU_NOTIFIER
select INTERVAL_TREE
default y
---help---
On demand paging support for the InfiniBand subsystem.

72
drivers/infiniband/core/umem_odp.c
View File

@ -39,45 +39,13 @@
#include <linux/export.h>
#include <linux/vmalloc.h>
#include <linux/hugetlb.h>
#include <linux/interval_tree_generic.h>
#include <linux/interval_tree.h>
#include <linux/pagemap.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_umem.h>
#include <rdma/ib_umem_odp.h>
/*
* The ib_umem list keeps track of memory regions for which the HW
* device request to receive notification when the related memory
* mapping is changed.
*
* ib_umem_lock protects the list.
*/
static u64 node_start(struct umem_odp_node *n)
{
struct ib_umem_odp *umem_odp =
container_of(n, struct ib_umem_odp, interval_tree);
return ib_umem_start(umem_odp);
}
/* Note that the representation of the intervals in the interval tree
* considers the ending point as contained in the interval, while the
* function ib_umem_end returns the first address which is not contained
* in the umem.
*/
static u64 node_last(struct umem_odp_node *n)
{
struct ib_umem_odp *umem_odp =
container_of(n, struct ib_umem_odp, interval_tree);
return ib_umem_end(umem_odp) - 1;
}
INTERVAL_TREE_DEFINE(struct umem_odp_node, rb, u64, __subtree_last,
node_start, node_last, static, rbt_ib_umem)
static void ib_umem_notifier_start_account(struct ib_umem_odp *umem_odp)
{
mutex_lock(&umem_odp->umem_mutex);
@ -205,9 +173,18 @@ static void add_umem_to_per_mm(struct ib_umem_odp *umem_odp)
struct ib_ucontext_per_mm *per_mm = umem_odp->per_mm;
down_write(&per_mm->umem_rwsem);
if (likely(ib_umem_start(umem_odp) != ib_umem_end(umem_odp)))
rbt_ib_umem_insert(&umem_odp->interval_tree,
&per_mm->umem_tree);
if (likely(ib_umem_start(umem_odp) != ib_umem_end(umem_odp))) {
/*
* Note that the representation of the intervals in the
* interval tree considers the ending point as contained in
* the interval, while the function ib_umem_end returns the
* first address which is not contained in the umem.
*/
umem_odp->interval_tree.start = ib_umem_start(umem_odp);
umem_odp->interval_tree.last = ib_umem_end(umem_odp) - 1;
interval_tree_insert(&umem_odp->interval_tree,
&per_mm->umem_tree);
}
up_write(&per_mm->umem_rwsem);
}
@ -217,8 +194,8 @@ static void remove_umem_from_per_mm(struct ib_umem_odp *umem_odp)
down_write(&per_mm->umem_rwsem);
if (likely(ib_umem_start(umem_odp) != ib_umem_end(umem_odp)))
rbt_ib_umem_remove(&umem_odp->interval_tree,
&per_mm->umem_tree);
interval_tree_remove(&umem_odp->interval_tree,
&per_mm->umem_tree);
complete_all(&umem_odp->notifier_completion);
up_write(&per_mm->umem_rwsem);
@ -761,18 +738,18 @@ int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
void *cookie)
{
int ret_val = 0;
struct umem_odp_node *node, *next;
struct interval_tree_node *node, *next;
struct ib_umem_odp *umem;
if (unlikely(start == last))
return ret_val;
for (node = rbt_ib_umem_iter_first(root, start, last - 1);
for (node = interval_tree_iter_first(root, start, last - 1);
node; node = next) {
/* TODO move the blockable decision up to the callback */
if (!blockable)
return -EAGAIN;
next = rbt_ib_umem_iter_next(node, start, last - 1);
next = interval_tree_iter_next(node, start, last - 1);
umem = container_of(node, struct ib_umem_odp, interval_tree);
ret_val = cb(umem, start, last, cookie) || ret_val;
}
@ -780,16 +757,3 @@ int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
return ret_val;
}
EXPORT_SYMBOL(rbt_ib_umem_for_each_in_range);
struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
u64 addr, u64 length)
{
struct umem_odp_node *node;
node = rbt_ib_umem_iter_first(root, addr, addr + length - 1);
if (node)
return container_of(node, struct ib_umem_odp, interval_tree);
return NULL;
}
EXPORT_SYMBOL(rbt_ib_umem_lookup);

20
include/rdma/ib_umem_odp.h
View File

@ -37,11 +37,6 @@
#include <rdma/ib_verbs.h>
#include <linux/interval_tree.h>
struct umem_odp_node {
u64 __subtree_last;
struct rb_node rb;
};
struct ib_umem_odp {
struct ib_umem umem;
struct ib_ucontext_per_mm *per_mm;
@ -72,7 +67,7 @@ struct ib_umem_odp {
int npages;
/* Tree tracking */
struct umem_odp_node interval_tree;
struct interval_tree_node interval_tree;
struct completion notifier_completion;
int dying;
@ -163,8 +158,17 @@ int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
* Find first region intersecting with address range.
* Return NULL if not found
*/
struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
u64 addr, u64 length);
static inline struct ib_umem_odp *
rbt_ib_umem_lookup(struct rb_root_cached *root, u64 addr, u64 length)
{
struct interval_tree_node *node;
node = interval_tree_iter_first(root, addr, addr + length - 1);
if (!node)
return NULL;
return container_of(node, struct ib_umem_odp, interval_tree);
}
static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp,
unsigned long mmu_seq)