| Message ID | 1456934187-4843-1-git-send-email-phil@nwl.cc |
|---|---|
| State | Accepted, archived |
| Delegated to: | stephen hemminger |
| Headers | show |
On Wed, 2 Mar 2016 16:56:27 +0100 Phil Sutter <phil@nwl.cc> wrote: > Since the relevant code (and it's bugs) is identical in both files, fix > them in one go. This patch fixes multiple issues: > > * Using 'int' for the 'tdiff' variable does not suffice on 64bit > systems, the assigned initial time difference makes it wrap and > contain a negative value afterwards. Instead use the more appropriate > 'time_t' type. > > * As far as I understood the code, poll() is supposed to time out just > at the right time to trigger update_db() in the configured interval. > Therefore it's timeout must be set to the desired interval *minus* the > time that has already passed since then. > > * With the last change to the algorithm in place, it does not make sense > to call update_db() before returning data to the connected client. > Actually, it never does otherwise we could skip the periodic updates > in the first place. > > Signed-off-by: Phil Sutter <phil@nwl.cc> Applied
diff --git a/misc/ifstat.c b/misc/ifstat.c index ac5c29c89184a..694d9839d2bd0 100644 --- a/misc/ifstat.c +++ b/misc/ifstat.c @@ -589,7 +589,7 @@ static void server_loop(int fd) for (;;) { int status; - int tdiff; + time_t tdiff; struct timeval now; gettimeofday(&now, NULL); @@ -600,7 +600,7 @@ static void server_loop(int fd) tdiff = 0; } - if (poll(&p, 1, tdiff + scan_interval) > 0 + if (poll(&p, 1, scan_interval - tdiff) > 0 && (p.revents&POLLIN)) { int clnt = accept(fd, NULL, NULL); if (clnt >= 0) { @@ -613,11 +613,8 @@ static void server_loop(int fd) close(clnt); } else { FILE *fp = fdopen(clnt, "w"); - if (fp) { - if (tdiff > 0) - update_db(tdiff); + if (fp) dump_raw_db(fp, 0); - } exit(0); } } diff --git a/misc/nstat.c b/misc/nstat.c index 99705286d279c..22b27eba7c8f6 100644 --- a/misc/nstat.c +++ b/misc/nstat.c @@ -433,7 +433,7 @@ static void server_loop(int fd) for (;;) { int status; - int tdiff; + time_t tdiff; struct timeval now; gettimeofday(&now, NULL); tdiff = T_DIFF(now, snaptime); @@ -442,7 +442,7 @@ static void server_loop(int fd) snaptime = now; tdiff = 0; } - if (poll(&p, 1, tdiff + scan_interval) > 0 + if (poll(&p, 1, scan_interval - tdiff) > 0 && (p.revents&POLLIN)) { int clnt = accept(fd, NULL, NULL); if (clnt >= 0) { @@ -455,11 +455,8 @@ static void server_loop(int fd) close(clnt); } else { FILE *fp = fdopen(clnt, "w"); - if (fp) { - if (tdiff > 0) - update_db(tdiff); + if (fp) dump_kern_db(fp, 0); - } exit(0); } }
Since the relevant code (and it's bugs) is identical in both files, fix them in one go. This patch fixes multiple issues: * Using 'int' for the 'tdiff' variable does not suffice on 64bit systems, the assigned initial time difference makes it wrap and contain a negative value afterwards. Instead use the more appropriate 'time_t' type. * As far as I understood the code, poll() is supposed to time out just at the right time to trigger update_db() in the configured interval. Therefore it's timeout must be set to the desired interval *minus* the time that has already passed since then. * With the last change to the algorithm in place, it does not make sense to call update_db() before returning data to the connected client. Actually, it never does otherwise we could skip the periodic updates in the first place. Signed-off-by: Phil Sutter <phil@nwl.cc> --- misc/ifstat.c | 9 +++------ misc/nstat.c | 9 +++------ 2 files changed, 6 insertions(+), 12 deletions(-)