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selftests: net: tcp_mmap: Use huge pages in send path

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There are significant gains using huge pages when
available, as shown in [1].

This patch adds mmap_large_buffer() and uses it
in client side (tx path of this reference tool)

Following patch will use the feature for server side.

[1] https://patchwork.ozlabs.org/project/netdev/patch/20200820154359.1806305-1-edumazet@google.com/

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2020-08-20 10:11:17 -07:00 committed by David S. Miller
parent 0d89419319
commit 72653ae530
1 changed files with 26 additions and 3 deletions
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29
tools/testing/selftests/net/tcp_mmap.c
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@ -123,6 +123,28 @@ void hash_zone(void *zone, unsigned int length)
#define ALIGN_UP(x, align_to) (((x) + ((align_to)-1)) & ~((align_to)-1))
#define ALIGN_PTR_UP(p, ptr_align_to) ((typeof(p))ALIGN_UP((unsigned long)(p), ptr_align_to))
static void *mmap_large_buffer(size_t need, size_t *allocated)
{
void *buffer;
size_t sz;
/* Attempt to use huge pages if possible. */
sz = ALIGN_UP(need, map_align);
buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
if (buffer == (void *)-1) {
sz = need;
buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (buffer != (void *)-1)
fprintf(stderr, "MAP_HUGETLB attempt failed, look at /sys/kernel/mm/hugepages for optimal performance\n");
}
*allocated = sz;
return buffer;
}
void *child_thread(void *arg)
{
unsigned long total_mmap = 0, total = 0;
@ -351,6 +373,7 @@ int main(int argc, char *argv[])
uint64_t total = 0;
char *host = NULL;
int fd, c, on = 1;
size_t buffer_sz;
char *buffer;
int sflg = 0;
int mss = 0;
@ -441,8 +464,8 @@ int main(int argc, char *argv[])
}
do_accept(fdlisten);
}
buffer = mmap(NULL, chunk_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
buffer = mmap_large_buffer(chunk_size, &buffer_sz);
if (buffer == (char *)-1) {
perror("mmap");
exit(1);
@ -488,6 +511,6 @@ int main(int argc, char *argv[])
total += wr;
}
close(fd);
munmap(buffer, chunk_size);
munmap(buffer, buffer_sz);
return 0;
}