From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <64ca22ab5ee16ec3a93db27d2b78fbe7@gmx.de>
To: 9fans@9fans.net
Date: Mon, 23 Mar 2009 00:13:31 +0100
From: cinap_lenrek@gmx.de
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Subject: [9fans] fossil periodic thread does zero sleep()
Topicbox-Message-UUID: c1d5129c-ead4-11e9-9d60-3106f5b1d025

Just noticed that the fsMetaFlush periodic thread in my fossil
pushes the syscall count in stats for some time now. Here is no
real load on the system and anything else works fine.

The questions are:

How to print double precisition floating point variables in acid?

Can anybody explain this fossil behaviour from the periodic code?

I checked that p->msec is 1000 in acid.

static void
periodicThread(void *a)
{
	Periodic *p = a;
	double t, ct, ts;

	vtThreadSetName("periodic");

	ct = nsec()*1e-6;
	t = ct + p->msec;

	for(;;){
		/* skip missed */
		while(t <= ct)
			t += p->msec;

		ts = t - ct;
		if(ts > 1000)
			ts = 1000;
		sleep(ts);
		ct = nsec()*1e-6;
		vtLock(p->lk);
		if(p->die){
			vtUnlock(p->lk);
			break;
		}
		if(t <= ct){
			p->f(p->a);
			t += p->msec;
		}
		vtUnlock(p->lk);
	}
	periodicFree(p);
}

Here is the stacktrace:

sleep()+0x7 /sys/src/libc/9syscall/sleep.s:5
periodicThread(a=0x8e8a60)+0xc9 /sys/src/cmd/fossil/periodic.c:70
	p=0x8e8a60
	ct=0x6721cc5a
	t=0x67601764
	ts=0x0
vtThread(rock=0x8e8a60,f=0x23291)+0x30 /sys/src/liboventi/plan9-thread.c:63
periodicAlloc(f=0x14933,a=0x7f690,msec=0x3e8)+0x54 /sys/src/cmd/fossil/periodic.c:30
	p=0x8e8a60
fsOpen(mode=0x1,file=0x5ce08,z=0x5ce88,ncache=0x3e8)+0x50f /sys/src/cmd/fossil/fs.c:125
	fd=0x9
	disk=0x7d4d0
	fs=0x7f690
	super=0x1
	b=0x817f0
	oscore=0x7d450
	bs=0x5ce88
fsysOpen(argv=0xdfffee88,argc=0x0,name=0x5ca2d)+0x12b /sys/src/cmd/fossil/9fsys.c:1568
	usage=0x3e219
	ncache=0x3e8
	noventi=0x0
	wstatallow=0x0
	noperm=0x0
	noauth=0x0
	rflag=0x1
	_argc=0xfdf00063
	_args=0x3e244
	p=0x5ca3e
	fsys=0x5aa08
fsysXXX(argv=0xdfffee80,name=0x5ca2d,argc=0x3)+0xec /sys/src/cmd/fossil/9fsys.c:1749
	i=0x2
	r=0x245a8
	fsys=0x2449f
cmdFsys(argc=0x4,argv=0xdfffee78)+0x13c /sys/src/cmd/fossil/9fsys.c:1813
	usage=0x3e399
	_argc=0x54d00005
	_args=0x32b4a
	fsys=0x5
cliExec(buf=0x51190)+0xe0 /sys/src/cmd/fossil/Ccli.c:58
	p=0x5ca28
	argv=0x5ca28
	argc=0x5
	i=0x8
	r=0x1
main(argv=0xdfffef74,argc=0x0)+0x15a /sys/src/cmd/fossil/fossil.c:129
	cmd=0x511d0
	tflag=0x0
	ncmd=0x5
	_argc=0x63
	_args=0x3e7ab
	p=0xdfffefba
	i=0x1
_main+0x31 /sys/src/libc/386/main9.s:16

--
cinap