Date: Wed, 21 Jan 2004 10:15:22 +0100 (CET) From: Divacky Roman <xdivac02@stud.fit.vutbr.cz> To: FreeBSD-gnats-submit@FreeBSD.org Subject: bin/61664: syslogd speedup Message-ID: <200401210915.i0L9FMgv094731@eva.fit.vutbr.cz> Resent-Message-ID: <200401210920.i0L9K6qx061091@freefall.freebsd.org>
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>Number: 61664
>Category: bin
>Synopsis: syslogd speedup
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: update
>Submitter-Id: current-users
>Arrival-Date: Wed Jan 21 01:20:06 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Divacky Roman
>Release: FreeBSD 4.9-STABLE i386
>Organization:
>Environment:
System: FreeBSD eva.fit.vutbr.cz 4.9-STABLE FreeBSD 4.9-STABLE #2: Thu Nov 20 11:20:53 CET 2003 root@tereza.fit.vutbr.cz:/home/src/sys/sys-49/compile/EVA i386
>Description:
When syslogd logs kernel messages it does it quite weird way. It reads
buffer from /dev/kmsg and then writes it into log file fsync()ing after
EACH newline.. this is very slow and much less secure than fsync()ing
it after whole buffer... this patch implements such behviour
>How-To-Repeat:
apply this patch ;)
>Fix:
--- syslogd.8 Mon Sep 8 21:57:22 2003
+++ /home/roman/kernel/patches/syslogd/syslogd.8 Wed Jan 14 17:21:14 2004
@@ -224,6 +224,9 @@
logged with each locally-written message. If specified more than once,
the names of the facility and priority are logged with each locally-written
message.
+.It Fl x
+Turns on old behaviour of fsync()ing after each line. This might make syslogd
+slower!
.El
.Pp
The
--- syslogd.c Sun Nov 16 22:51:06 2003
+++ /home/roman/kernel/patches/syslogd/syslogd.c Wed Jan 14 17:27:14 2004
@@ -288,6 +288,7 @@
static int LogFacPri; /* Put facility and priority in log message: */
/* 0=no, 1=numeric, 2=names */
static int KeepKernFac; /* Keep remotely logged kernel facility */
+static int DoFsync; /* wheter do a fsync() on boot */
volatile sig_atomic_t MarkSet, WantDie;
@@ -310,7 +311,7 @@
static void markit(void);
static int skip_message(const char *, const char *, int);
static void printline(const char *, char *);
-static void printsys(char *);
+static void printsys(char *, int);
static int p_open(const char *, pid_t *);
static void readklog(void);
static void reapchild(int);
@@ -338,7 +339,7 @@
socklen_t len;
bindhostname = NULL;
- while ((ch = getopt(argc, argv, "46Aa:b:cdf:kl:m:nop:P:suv")) != -1)
+ while ((ch = getopt(argc, argv, "46Aa:b:cdf:kl:m:nop:P:suvx")) != -1)
switch (ch) {
case '4':
family = PF_INET;
@@ -401,6 +402,9 @@
case 'v': /* log facility and priority */
LogFacPri++;
break;
+ case 'x':
+ DoFsync++; /* Do fsync() */
+ break;
case '?':
default:
usage();
@@ -716,29 +720,34 @@
for (p = line; (q = strchr(p, '\n')) != NULL; p = q + 1) {
*q = '\0';
- printsys(p);
+ printsys(p, ISKERNEL | ADDDATE);
}
len = strlen(p);
if (len >= MAXLINE - 1) {
- printsys(p);
+ printsys(p, ISKERNEL | ADDDATE);
len = 0;
}
+ /* XXX: This could be as well on the end of this function */
+ if (!DoFsync)
+ fsync (Files->f_file);
if (len > 0)
memmove(line, p, len + 1);
}
if (len > 0)
- printsys(line);
+ printsys(line, ISKERNEL | ADDDATE | SYNC_FILE);
}
/*
* Take a raw input line from /dev/klog, format similar to syslog().
*/
static void
-printsys(char *p)
+printsys(char *p, int flags)
{
- int pri, flags;
+ int pri;
- flags = ISKERNEL | SYNC_FILE | ADDDATE; /* fsync after write */
+ if (DoFsync)
+ flags |= SYNC_FILE; /* fsync after write */
+
pri = DEFSPRI;
if (*p == '<') {
pri = 0;
>Release-Note:
>Audit-Trail:
>Unformatted:
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