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v0.6.0
v0.6.0
Revision a0783cd0c810504427777e8aae20d5f4f8b652a0 authored by Corinna Vinschen on 19 November 2019, 09:09:39 UTC, committed by David S. Miller on 20 November 2019, 00:41:11 UTC
During performance testing, I found that one of my r8169 NICs suffered a major performance loss, a 8168c model. Running netperf's TCP_STREAM test didn't return the expected throughput of > 900 Mb/s, but rather only about 22 Mb/s. Strange enough, running the TCP_MAERTS and UDP_STREAM tests all returned with throughput > 900 Mb/s, as did TCP_STREAM with the other r8169 NICs I can test (either one of 8169s, 8168e, 8168f). Bisecting turned up commit 93681cd7d94f83903cb3f0f95433d10c28a7e9a5, "r8169: enable HW csum and TSO" as the culprit. I added my 8168c version, RTL_GIGA_MAC_VER_22, to the code special-casing the 8168evl as per the patch below. This fixed the performance problem for me. Fixes: 93681cd7d94f ("r8169: enable HW csum and TSO") Signed-off-by: Corinna Vinschen <vinschen@redhat.com> Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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generic-radix-tree.c
#include <linux/export.h>
#include <linux/generic-radix-tree.h>
#include <linux/gfp.h>
#include <linux/kmemleak.h>
#define GENRADIX_ARY (PAGE_SIZE / sizeof(struct genradix_node *))
#define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY)
struct genradix_node {
union {
/* Interior node: */
struct genradix_node *children[GENRADIX_ARY];
/* Leaf: */
u8 data[PAGE_SIZE];
};
};
static inline int genradix_depth_shift(unsigned depth)
{
return PAGE_SHIFT + GENRADIX_ARY_SHIFT * depth;
}
/*
* Returns size (of data, in bytes) that a tree of a given depth holds:
*/
static inline size_t genradix_depth_size(unsigned depth)
{
return 1UL << genradix_depth_shift(depth);
}
/* depth that's needed for a genradix that can address up to ULONG_MAX: */
#define GENRADIX_MAX_DEPTH \
DIV_ROUND_UP(BITS_PER_LONG - PAGE_SHIFT, GENRADIX_ARY_SHIFT)
#define GENRADIX_DEPTH_MASK \
((unsigned long) (roundup_pow_of_two(GENRADIX_MAX_DEPTH + 1) - 1))
static inline unsigned genradix_root_to_depth(struct genradix_root *r)
{
return (unsigned long) r & GENRADIX_DEPTH_MASK;
}
static inline struct genradix_node *genradix_root_to_node(struct genradix_root *r)
{
return (void *) ((unsigned long) r & ~GENRADIX_DEPTH_MASK);
}
/*
* Returns pointer to the specified byte @offset within @radix, or NULL if not
* allocated
*/
void *__genradix_ptr(struct __genradix *radix, size_t offset)
{
struct genradix_root *r = READ_ONCE(radix->root);
struct genradix_node *n = genradix_root_to_node(r);
unsigned level = genradix_root_to_depth(r);
if (ilog2(offset) >= genradix_depth_shift(level))
return NULL;
while (1) {
if (!n)
return NULL;
if (!level)
break;
level--;
n = n->children[offset >> genradix_depth_shift(level)];
offset &= genradix_depth_size(level) - 1;
}
return &n->data[offset];
}
EXPORT_SYMBOL(__genradix_ptr);
static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask)
{
struct genradix_node *node;
node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO);
/*
* We're using pages (not slab allocations) directly for kernel data
* structures, so we need to explicitly inform kmemleak of them in order
* to avoid false positive memory leak reports.
*/
kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask);
return node;
}
static inline void genradix_free_node(struct genradix_node *node)
{
kmemleak_free(node);
free_page((unsigned long)node);
}
/*
* Returns pointer to the specified byte @offset within @radix, allocating it if
* necessary - newly allocated slots are always zeroed out:
*/
void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
gfp_t gfp_mask)
{
struct genradix_root *v = READ_ONCE(radix->root);
struct genradix_node *n, *new_node = NULL;
unsigned level;
/* Increase tree depth if necessary: */
while (1) {
struct genradix_root *r = v, *new_root;
n = genradix_root_to_node(r);
level = genradix_root_to_depth(r);
if (n && ilog2(offset) < genradix_depth_shift(level))
break;
if (!new_node) {
new_node = genradix_alloc_node(gfp_mask);
if (!new_node)
return NULL;
}
new_node->children[0] = n;
new_root = ((struct genradix_root *)
((unsigned long) new_node | (n ? level + 1 : 0)));
if ((v = cmpxchg_release(&radix->root, r, new_root)) == r) {
v = new_root;
new_node = NULL;
}
}
while (level--) {
struct genradix_node **p =
&n->children[offset >> genradix_depth_shift(level)];
offset &= genradix_depth_size(level) - 1;
n = READ_ONCE(*p);
if (!n) {
if (!new_node) {
new_node = genradix_alloc_node(gfp_mask);
if (!new_node)
return NULL;
}
if (!(n = cmpxchg_release(p, NULL, new_node)))
swap(n, new_node);
}
}
if (new_node)
genradix_free_node(new_node);
return &n->data[offset];
}
EXPORT_SYMBOL(__genradix_ptr_alloc);
void *__genradix_iter_peek(struct genradix_iter *iter,
struct __genradix *radix,
size_t objs_per_page)
{
struct genradix_root *r;
struct genradix_node *n;
unsigned level, i;
restart:
r = READ_ONCE(radix->root);
if (!r)
return NULL;
n = genradix_root_to_node(r);
level = genradix_root_to_depth(r);
if (ilog2(iter->offset) >= genradix_depth_shift(level))
return NULL;
while (level) {
level--;
i = (iter->offset >> genradix_depth_shift(level)) &
(GENRADIX_ARY - 1);
while (!n->children[i]) {
i++;
iter->offset = round_down(iter->offset +
genradix_depth_size(level),
genradix_depth_size(level));
iter->pos = (iter->offset >> PAGE_SHIFT) *
objs_per_page;
if (i == GENRADIX_ARY)
goto restart;
}
n = n->children[i];
}
return &n->data[iter->offset & (PAGE_SIZE - 1)];
}
EXPORT_SYMBOL(__genradix_iter_peek);
static void genradix_free_recurse(struct genradix_node *n, unsigned level)
{
if (level) {
unsigned i;
for (i = 0; i < GENRADIX_ARY; i++)
if (n->children[i])
genradix_free_recurse(n->children[i], level - 1);
}
genradix_free_node(n);
}
int __genradix_prealloc(struct __genradix *radix, size_t size,
gfp_t gfp_mask)
{
size_t offset;
for (offset = 0; offset < size; offset += PAGE_SIZE)
if (!__genradix_ptr_alloc(radix, offset, gfp_mask))
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(__genradix_prealloc);
void __genradix_free(struct __genradix *radix)
{
struct genradix_root *r = xchg(&radix->root, NULL);
genradix_free_recurse(genradix_root_to_node(r),
genradix_root_to_depth(r));
}
EXPORT_SYMBOL(__genradix_free);
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