Date: Tue, 03 May 2011 13:38:44 +0200 From: Alexander Leidinger <Alexander@Leidinger.net> To: John Baldwin <jhb@freebsd.org> Cc: Kostik Belousov <kostikbel@gmail.com>, arch@freebsd.org Subject: Re: [PATCH] Add ktrace records for user page faults Message-ID: <20110503133844.184523llr0156o9w@webmail.leidinger.net> In-Reply-To: <201105021602.02668.jhb@freebsd.org> References: <201105021537.19507.jhb@freebsd.org> <20110502195555.GC48734@deviant.kiev.zoral.com.ua> <201105021602.02668.jhb@freebsd.org>
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Quoting John Baldwin <jhb@freebsd.org> (from Mon, 2 May 2011 16:02:02 -0400): > It is true that it would be nice to have the exact faulting address, though > having page granularity has been sufficient for the few times I've actually > used the address itself (e.g. I could figure out which page of libstdc++ a > fault occurred on and narrow down from there as to which of the routines most > likely was executed given what the app was doing at the time). In my case > knowing how much time was spent handling a page fault has been useful. > > Would we have to push this logic out of vm_fault and into every > trap() routine > to get the original address? That would make the patch quite a bit bigger > (touching N MD files vs 1 MI file). dtrace is not a solution here (in general, not to the exact-address problem)? Bye, Alexander. -- I am looking for a honest man. -- Diogenes the Cynic http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137
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