Date: Thu, 16 Dec 2004 23:50:11 -0500 From: Suleiman Souhlal <ssouhlal@FreeBSD.org> To: Max Laier <max@love2party.net> Cc: freebsd-arch@FreeBSD.org Subject: Re: sysctl locking Message-ID: <21F934EB-4FE7-11D9-B1F7-000A95C4D7BC@FreeBSD.org> In-Reply-To: <200412131232.55051.max@love2party.net> References: <94AE3F5A-4CD6-11D9-8BD6-000A95C4D7BC@FreeBSD.org> <200412130913.20215.max@love2party.net> <200412131232.55051.max@love2party.net>
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Hello, On Dec 13, 2004, at 6:32 AM, Max Laier wrote: > 1) Extend sysctl_add_oid() to accept an additional mutex argument. > 2) Extend the simple sysctl handler to use this mutex to protect the > actual > write(?read?). We must not hold the mutex during the useland copy > in/out so > we must move to temporary storage. > 3) To maintain the current API and behavior we use &Giant as the > default > fallback argument. This might need some extension for complex > handler (i.e. > no mutex given -> acquire Giant before calling the complex handler). > > What do people think of this? Does it make any sense? Should we be > concerned > at all? Does the extension make sense? Comments? I have implemented this. The diff is at http://people.freebsd.org/~ssouhlal/sysctl-sx-locking-20041214.diff It also needs the patch at http://people.freebsd.org/~ssouhlal/sx_xlocked.diff which introduces a sx_xlocked() function. Unfortunately, we still need to look at every single SYSCTL_PROC, and make either grab Giant, lock correctly, or make sure it doesn't need any locking. :( -- Suleiman Souhlal | ssouhlal@vt.edu The FreeBSD Project | ssouhlal@FreeBSD.org _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"
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