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author | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2013-04-06 10:05:59 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2013-04-08 15:26:32 +0200 |
commit | ab7d9b674e8eb1388dff4d44def1b661892832e6 (patch) | |
tree | 240db615184028e12ff1743389625c6151dfb752 /src/shared/dbus-common.h | |
parent | b6b7d4337976eeac610b9ed2c3e1fd596a247b14 (diff) |
util: Avoid memory allocations for formatting paths
Avoid memory allocations to construct the path for files in the
procfs. The procfs paths are way shorter than the PATH_MAX so we
can use snprintf on a string located on the stack. This shows up
as a win on x86 using the benchmark program below.
$ make libsystemd-shared.la; gcc -O2 -Isrc/systemd/ -Isrc/ \
-o simple-perf-test simple-perf-test.c \
.libs/libsystemd-shared.a -lrt
#include "shared/util.h"
void test_once(void) {
pid_t pid = getpid();
char *tmp = NULL;
get_process_comm(pid, &tmp);
free(tmp);
tmp = NULL;
get_process_cmdline(pid, 0, 1, &tmp);
free(tmp);
is_kernel_thread(pid);
tmp = NULL;
get_process_exe(pid, &tmp);
free(tmp);
}
int main(int argc, char **argv)
{
int i;
for (i = 0; i < 50000; ++i)
test_once();
}
Diffstat (limited to 'src/shared/dbus-common.h')
0 files changed, 0 insertions, 0 deletions