iowatcher: spawn NPROCESSORS_ONLN for rsvg-convert-s
iowatcher currently always spawns 8 rsvg-convert processes, no matter
how many CPUs a system has. I did some limited testing of different
numbers of rsvg-convert processes. Here are the results:
8 processes:
real 4m2.194s
user 23m36.665s
sys 0m38.523s
20 processes:
real 2m28.935s
user 24m51.817s
sys 0m49.227s
40 processes:
real 2m28.150s
user 24m56.994s
sys 0m49.621s
Note that this is the time it takes for a full run of iowatcher -- I
didn't separate out just the rsvg-convert portion.
Given the above results, it seems like a reasonable thing to spawn one
rsvg-convert process per cpu.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/iowatcher/main.c b/iowatcher/main.c
index 54325fb..4b97013 100644
--- a/iowatcher/main.c
+++ b/iowatcher/main.c
@@ -1043,9 +1043,14 @@
static void convert_movie_files(char *movie_dir)
{
+ long nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+
+ if (nr_cpus < 0)
+ nr_cpus = 8;
+
fprintf(stderr, "Converting svg files in %s\n", movie_dir);
- snprintf(line, line_len, "find %s -name \\*.svg | xargs -I{} -n 1 -P 8 rsvg-convert -o {}.png {}",
- movie_dir);
+ snprintf(line, line_len, "find %s -name \\*.svg | xargs -I{} -n 1 -P %ld rsvg-convert -o {}.png {}",
+ movie_dir, nr_cpus);
system_check(line);
}
