From owner-freebsd-current  Mon Nov  5 14:30:27 2001
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Date: Mon, 5 Nov 2001 14:26:48 -0800
From: Luigi Rizzo <rizzo@aciri.org>
To: current@freebsd.org
Subject: when to use XX_LOCK() ?
Message-ID: <20011105142648.E76687@iguana.aciri.org>
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In if_dc.c and other places, i see sequences like this:

	dc_intr(arg) {
		struct dc_softc sc;

		sc = arg;
		DC_LOCK(sc);
		ifp = &sc->arpcom.ac_if;
		...

Wondering: any reason to call DC_LOCK before assigning a value to ifp ?
Nobody is going to change it without taking away the device
(which contains the lock itself).

	cheers
	luigi


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