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Date: Wed, 2 Mar 2016 16:56:27 +0100
From: Phil Sutter <phil@....cc>
To: Stephen Hemminger <shemming@...cade.com>
Cc: netdev@...r.kernel.org
Subject: [iproute PATCH] ifstat, nstat: fix daemon mode
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@....cc>
---
misc/ifstat.c | 9 +++------
misc/nstat.c | 9 +++------
2 files changed, 6 insertions(+), 12 deletions(-)
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);
}
}
--
2.7.2
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