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dma-mapping: benchmark: Add support for multi-pages map/unmap 

Currently it only support one page map/unmap once a time for dma-map
benchmark, but there are some other scenaries which need to support for
multi-page map/unmap: for those multi-pages interfaces such as
dma_alloc_coherent() and dma_map_sg(), the time spent on multi-pages
map/unmap is not the time of a single page * npages (not linear) as it
may use block description instead of page description when it is satified
with the size such as 2M/1G, and also it can send a single TLB invalidation
command to invalidate multi-pages instead of multi-times when RIL is
enabled (which will short the time of unmap). So it is necessary to add
support for multi-pages map/unmap.

Add a parameter "-g" to support multi-pages map/unmap.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Xiang Chen 2021-03-18 17:29:30 +08:00 committed by Christoph Hellwig
parent 42e4eefb08
commit ca947482b0
2 changed files with 30 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
kernel/dma/map_benchmark.c
View File

@ -38,7 +38,8 @@ struct map_benchmark {
__u32 dma_bits; /* DMA addressing capability */
__u32 dma_dir; /* DMA data direction */
__u32 dma_trans_ns; /* time for DMA transmission in ns */
__u8 expansion[80]; /* For future use */
__u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
__u8 expansion[76]; /* For future use */
};
struct map_benchmark_data {
@ -58,9 +59,11 @@ static int map_benchmark_thread(void *data)
void *buf;
dma_addr_t dma_addr;
struct map_benchmark_data *map = data;
int npages = map->bparam.granule;
u64 size = npages * PAGE_SIZE;
int ret = 0;
buf = (void *)__get_free_page(GFP_KERNEL);
buf = alloc_pages_exact(size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@ -76,10 +79,10 @@ static int map_benchmark_thread(void *data)
* 66 means evertything goes well! 66 is lucky.
*/
if (map->dir != DMA_FROM_DEVICE)
memset(buf, 0x66, PAGE_SIZE);
memset(buf, 0x66, size);
map_stime = ktime_get();
dma_addr = dma_map_single(map->dev, buf, PAGE_SIZE, map->dir);
dma_addr = dma_map_single(map->dev, buf, size, map->dir);
if (unlikely(dma_mapping_error(map->dev, dma_addr))) {
pr_err("dma_map_single failed on %s\n",
dev_name(map->dev));
@ -93,7 +96,7 @@ static int map_benchmark_thread(void *data)
ndelay(map->bparam.dma_trans_ns);
unmap_stime = ktime_get();
dma_unmap_single(map->dev, dma_addr, PAGE_SIZE, map->dir);
dma_unmap_single(map->dev, dma_addr, size, map->dir);
unmap_etime = ktime_get();
unmap_delta = ktime_sub(unmap_etime, unmap_stime);
@ -112,7 +115,7 @@ static int map_benchmark_thread(void *data)
}
out:
free_page((unsigned long)buf);
free_pages_exact(buf, size);
return ret;
}
@ -203,7 +206,6 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
struct map_benchmark_data *map = file->private_data;
void __user *argp = (void __user *)arg;
u64 old_dma_mask;
int ret;
if (copy_from_user(&map->bparam, argp, sizeof(map->bparam)))
@ -234,6 +236,11 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
return -EINVAL;
}
if (map->bparam.granule < 1 || map->bparam.granule > 1024) {
pr_err("invalid granule size\n");
return -EINVAL;
}
switch (map->bparam.dma_dir) {
case DMA_MAP_BIDIRECTIONAL:
map->dir = DMA_BIDIRECTIONAL;

20
tools/testing/selftests/dma/dma_map_benchmark.c
View File

@ -40,7 +40,8 @@ struct map_benchmark {
__u32 dma_bits; /* DMA addressing capability */
__u32 dma_dir; /* DMA data direction */
__u32 dma_trans_ns; /* time for DMA transmission in ns */
__u8 expansion[80]; /* For future use */
__u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
__u8 expansion[76]; /* For future use */
};
int main(int argc, char **argv)
@ -51,11 +52,13 @@ int main(int argc, char **argv)
int threads = 1, seconds = 20, node = -1;
/* default dma mask 32bit, bidirectional DMA */
int bits = 32, xdelay = 0, dir = DMA_MAP_BIDIRECTIONAL;
/* default granule 1 PAGESIZE */
int granule = 1;
int cmd = DMA_MAP_BENCHMARK;
char *p;
while ((opt = getopt(argc, argv, "t:s:n:b:d:x:")) != -1) {
while ((opt = getopt(argc, argv, "t:s:n:b:d:x:g:")) != -1) {
switch (opt) {
case 't':
threads = atoi(optarg);
@ -75,6 +78,9 @@ int main(int argc, char **argv)
case 'x':
xdelay = atoi(optarg);
break;
case 'g':
granule = atoi(optarg);
break;
default:
return -1;
}
@ -110,6 +116,11 @@ int main(int argc, char **argv)
exit(1);
}
if (granule < 1 || granule > 1024) {
fprintf(stderr, "invalid granule size\n");
exit(1);
}
fd = open("/sys/kernel/debug/dma_map_benchmark", O_RDWR);
if (fd == -1) {
perror("open");
@ -123,14 +134,15 @@ int main(int argc, char **argv)
map.dma_bits = bits;
map.dma_dir = dir;
map.dma_trans_ns = xdelay;
map.granule = granule;
if (ioctl(fd, cmd, &map)) {
perror("ioctl");
exit(1);
}
printf("dma mapping benchmark: threads:%d seconds:%d node:%d dir:%s\n",
threads, seconds, node, dir[directions]);
printf("dma mapping benchmark: threads:%d seconds:%d node:%d dir:%s granule: %d\n",
threads, seconds, node, dir[directions], granule);
printf("average map latency(us):%.1f standard deviation:%.1f\n",
map.avg_map_100ns/10.0, map.map_stddev/10.0);
printf("average unmap latency(us):%.1f standard deviation:%.1f\n",