Commit e6e67768 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tcp_mmap-optmizations' 



Eric Dumazet says:

====================
tcp_mmap: optmizations

This series updates tcp_mmap reference tool to use best pratices.

First patch is using madvise(MADV_DONTNEED) to decrease pressure
on the socket lock.

Last patches try to use huge pages when available.
====================

Acked-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: default avatarArjun Roy <arjunroy@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 394fcd8a 59c0d319

tools/testing/selftests/net/tcp_mmap.c

+35 −7
Original line number Diff line number Diff line
@@ -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;
@@ -135,6 +157,7 @@ void *child_thread(void *arg) 
	void *addr = NULL;

	double throughput;

	struct rusage ru;

	size_t buffer_sz;

	int lu, fd;



	fd = (int)(unsigned long)arg;
@@ -142,9 +165,9 @@ void *child_thread(void *arg) 
	gettimeofday(&t0, NULL);



	fcntl(fd, F_SETFL, O_NDELAY);

	buffer = malloc(chunk_size);

	if (!buffer) {

		perror("malloc");

	buffer = mmap_large_buffer(chunk_size, &buffer_sz);

	if (buffer == (void *)-1) {

		perror("mmap");

		goto error;

	}

	if (zflg) {
@@ -179,6 +202,10 @@ void *child_thread(void *arg) 
				total_mmap += zc.length;

				if (xflg)

					hash_zone(addr, zc.length);

				/* It is more efficient to unmap the pages right now,

				 * instead of doing this in next TCP_ZEROCOPY_RECEIVE.

				 */

				madvise(addr, zc.length, MADV_DONTNEED);

				total += zc.length;

			}

			if (zc.recv_skip_hint) {
@@ -230,7 +257,7 @@ end: 
				ru.ru_nvcsw);

	}

error:

	free(buffer);

	munmap(buffer, buffer_sz);

	close(fd);

	if (zflg)

		munmap(raddr, chunk_size + map_align);
@@ -347,6 +374,7 @@ 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;
@@ -437,8 +465,8 @@ 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);
@@ -484,6 +512,6 @@ int main(int argc, char *argv[]) 
		total += wr;

	}

	close(fd);

	munmap(buffer, chunk_size);

	munmap(buffer, buffer_sz);

	return 0;

}

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