[v4] test: optimise fd closing in forked test process
Checks
Commit Message
From: Krzysztof Kanas <kkanas@marvell.com>
Caught while investigating timeouts on a ARM64 server.
Stracing a test process running the eal_flags_autotest, we can see that
the fork helper is checking all possible file descriptors from
getdtablesize() to 2, and close the existing ones.
We can do better by inspecting this forked process /proc/self/fd
directory.
Besides, checking file descriptors via /proc/self/fd only makes sense for
Linux. This code was a noop on FreeBSD.
Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Krzysztof Kanas <kkanas@marvell.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changelog since v3:
- rewrote commit log message,
- restricted the fix to Linux only,
---
app/test/process.h | 50 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 44 insertions(+), 6 deletions(-)
Comments
On 12/11/2019 20:31, David Marchand wrote:
> From: Krzysztof Kanas <kkanas@marvell.com>
>
> Caught while investigating timeouts on a ARM64 server.
>
> Stracing a test process running the eal_flags_autotest, we can see that
> the fork helper is checking all possible file descriptors from
> getdtablesize() to 2, and close the existing ones.
> We can do better by inspecting this forked process /proc/self/fd
> directory.
>
> Besides, checking file descriptors via /proc/self/fd only makes sense for
> Linux. This code was a noop on FreeBSD.
>
> Fixes: af75078fece3 ("first public release")
> Cc: stable@dpdk.org
>
> Signed-off-by: Krzysztof Kanas <kkanas@marvell.com>
> Signed-off-by: David Marchand <david.marchand@redhat.com>
Seems to be an improvement on what is existing.
Acked-by: Kevin Traynor <ktraynor@redhat.com>
On Thu, Nov 14, 2019 at 8:32 PM Kevin Traynor <ktraynor@redhat.com> wrote:
>
> On 12/11/2019 20:31, David Marchand wrote:
> > From: Krzysztof Kanas <kkanas@marvell.com>
> >
> > Caught while investigating timeouts on a ARM64 server.
> >
> > Stracing a test process running the eal_flags_autotest, we can see that
> > the fork helper is checking all possible file descriptors from
> > getdtablesize() to 2, and close the existing ones.
> > We can do better by inspecting this forked process /proc/self/fd
> > directory.
> >
> > Besides, checking file descriptors via /proc/self/fd only makes sense for
> > Linux. This code was a noop on FreeBSD.
> >
> > Fixes: af75078fece3 ("first public release")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Krzysztof Kanas <kkanas@marvell.com>
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
Tested-by: Krzysztof Kanas <kkanas@marvell.com>
> Seems to be an improvement on what is existing.
>
> Acked-by: Kevin Traynor <ktraynor@redhat.com>
>
Applied, thanks.
--
David Marchand
@@ -11,6 +11,7 @@
#include <stdlib.h> /* NULL */
#include <string.h> /* strerror */
#include <unistd.h> /* readlink */
+#include <dirent.h>
#include <sys/wait.h>
#include <rte_string_fns.h> /* strlcpy */
@@ -40,7 +41,7 @@ process_dup(const char *const argv[], int numargs, const char *env_value)
{
int num;
char *argv_cpy[numargs + 1];
- int i, fd, status;
+ int i, status;
char path[32];
#ifdef RTE_LIBRTE_PDUMP
pthread_t thread;
@@ -56,13 +57,50 @@ process_dup(const char *const argv[], int numargs, const char *env_value)
argv_cpy[i] = NULL;
num = numargs;
- /* close all open file descriptors, check /proc/self/fd to only
- * call close on open fds. Exclude fds 0, 1 and 2*/
- for (fd = getdtablesize(); fd > 2; fd-- ) {
- snprintf(path, sizeof(path), "/proc/" exe "/fd/%d", fd);
- if (access(path, F_OK) == 0)
+#ifdef RTE_EXEC_ENV_LINUX
+ {
+ const char *procdir = "/proc/" self "/fd/";
+ struct dirent *dirent;
+ char *endptr;
+ int fd, fdir;
+ DIR *dir;
+
+ /* close all open file descriptors, check /proc/self/fd
+ * to only call close on open fds. Exclude fds 0, 1 and
+ * 2
+ */
+ dir = opendir(procdir);
+ if (dir == NULL) {
+ rte_panic("Error opening %s: %s\n", procdir,
+ strerror(errno));
+ }
+
+ fdir = dirfd(dir);
+ if (fdir < 0) {
+ status = errno;
+ closedir(dir);
+ rte_panic("Error %d obtaining fd for dir %s: %s\n",
+ fdir, procdir,
+ strerror(status));
+ }
+
+ while ((dirent = readdir(dir)) != NULL) {
+ errno = 0;
+ fd = strtol(dirent->d_name, &endptr, 10);
+ if (errno != 0 || endptr[0] != '\0') {
+ printf("Error converting name fd %d %s:\n",
+ fd, dirent->d_name);
+ continue;
+ }
+
+ if (fd == fdir || fd <= 2)
+ continue;
+
close(fd);
+ }
+ closedir(dir);
}
+#endif
printf("Running binary with argv[]:");
for (i = 0; i < num; i++)
printf("'%s' ", argv_cpy[i]);