Staging
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>
1 parent c9d55b6
test_string.c
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
static __init int memset16_selftest(void)
{
unsigned i, j, k;
u16 v, *p;
p = kmalloc(256 * 2 * 2, GFP_KERNEL);
if (!p)
return -1;
for (i = 0; i < 256; i++) {
for (j = 0; j < 256; j++) {
memset(p, 0xa1, 256 * 2 * sizeof(v));
memset16(p + i, 0xb1b2, j);
for (k = 0; k < 512; k++) {
v = p[k];
if (k < i) {
if (v != 0xa1a1)
goto fail;
} else if (k < i + j) {
if (v != 0xb1b2)
goto fail;
} else {
if (v != 0xa1a1)
goto fail;
}
}
}
}
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}
static __init int memset32_selftest(void)
{
unsigned i, j, k;
u32 v, *p;
p = kmalloc(256 * 2 * 4, GFP_KERNEL);
if (!p)
return -1;
for (i = 0; i < 256; i++) {
for (j = 0; j < 256; j++) {
memset(p, 0xa1, 256 * 2 * sizeof(v));
memset32(p + i, 0xb1b2b3b4, j);
for (k = 0; k < 512; k++) {
v = p[k];
if (k < i) {
if (v != 0xa1a1a1a1)
goto fail;
} else if (k < i + j) {
if (v != 0xb1b2b3b4)
goto fail;
} else {
if (v != 0xa1a1a1a1)
goto fail;
}
}
}
}
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}
static __init int memset64_selftest(void)
{
unsigned i, j, k;
u64 v, *p;
p = kmalloc(256 * 2 * 8, GFP_KERNEL);
if (!p)
return -1;
for (i = 0; i < 256; i++) {
for (j = 0; j < 256; j++) {
memset(p, 0xa1, 256 * 2 * sizeof(v));
memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
for (k = 0; k < 512; k++) {
v = p[k];
if (k < i) {
if (v != 0xa1a1a1a1a1a1a1a1ULL)
goto fail;
} else if (k < i + j) {
if (v != 0xb1b2b3b4b5b6b7b8ULL)
goto fail;
} else {
if (v != 0xa1a1a1a1a1a1a1a1ULL)
goto fail;
}
}
}
}
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}
static __init int strchr_selftest(void)
{
const char *test_string = "abcdefghijkl";
const char *empty_string = "";
char *result;
int i;
for (i = 0; i < strlen(test_string) + 1; i++) {
result = strchr(test_string, test_string[i]);
if (result - test_string != i)
return i + 'a';
}
result = strchr(empty_string, '\0');
if (result != empty_string)
return 0x101;
result = strchr(empty_string, 'a');
if (result)
return 0x102;
result = strchr(test_string, 'z');
if (result)
return 0x103;
return 0;
}
static __init int strnchr_selftest(void)
{
const char *test_string = "abcdefghijkl";
const char *empty_string = "";
char *result;
int i, j;
for (i = 0; i < strlen(test_string) + 1; i++) {
for (j = 0; j < strlen(test_string) + 2; j++) {
result = strnchr(test_string, j, test_string[i]);
if (j <= i) {
if (!result)
continue;
return ((i + 'a') << 8) | j;
}
if (result - test_string != i)
return ((i + 'a') << 8) | j;
}
}
result = strnchr(empty_string, 0, '\0');
if (result)
return 0x10001;
result = strnchr(empty_string, 1, '\0');
if (result != empty_string)
return 0x10002;
result = strnchr(empty_string, 1, 'a');
if (result)
return 0x10003;
result = strnchr(NULL, 0, '\0');
if (result)
return 0x10004;
return 0;
}
static __init int string_selftest_init(void)
{
int test, subtest;
test = 1;
subtest = memset16_selftest();
if (subtest)
goto fail;
test = 2;
subtest = memset32_selftest();
if (subtest)
goto fail;
test = 3;
subtest = memset64_selftest();
if (subtest)
goto fail;
test = 4;
subtest = strchr_selftest();
if (subtest)
goto fail;
test = 5;
subtest = strnchr_selftest();
if (subtest)
goto fail;
pr_info("String selftests succeeded\n");
return 0;
fail:
pr_crit("String selftest failure %d.%08x\n", test, subtest);
return 0;
}
module_init(string_selftest_init);
MODULE_LICENSE("GPL v2");
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