Currently it parses the /proc file everytime it opens a file in the cgroupfs. Save the last result to avoid it (assuming it won't be changed between the accesses).
Signed-off-by: Namhyung Kim <[email protected]> --- tools/lib/api/fs/cgroup.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/lib/api/fs/cgroup.c b/tools/lib/api/fs/cgroup.c index 262a4229e293..1573dae4259d 100644 --- a/tools/lib/api/fs/cgroup.c +++ b/tools/lib/api/fs/cgroup.c @@ -8,6 +8,14 @@ #include <string.h> #include "fs.h" +struct cgroupfs_cache_entry { + char subsys[32]; + char mountpoint[PATH_MAX]; +}; + +/* just cache last used one */ +static struct cgroupfs_cache_entry cached; + int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys) { FILE *fp; @@ -16,6 +24,14 @@ int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys) char *p, *path; char mountpoint[PATH_MAX]; + if (!strcmp(cached.subsys, subsys)) { + if (strlen(cached.mountpoint) < maxlen) { + strcpy(buf, cached.mountpoint); + return 0; + } + return -1; + } + fp = fopen("/proc/mounts", "r"); if (!fp) return -1; @@ -75,6 +91,9 @@ int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys) free(line); fclose(fp); + strncpy(cached.subsys, subsys, sizeof(cached.subsys) - 1); + strcpy(cached.mountpoint, mountpoint); + if (mountpoint[0] && strlen(mountpoint) < maxlen) { strcpy(buf, mountpoint); return 0; -- 2.29.2.684.gfbc64c5ab5-goog
