Date: Tue, 28 Sep 2010 21:36:11 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: John Baldwin <jhb@freebsd.org> Cc: bruce@cran.org.uk, src-committers@freebsd.org, Ken Smith <kensmith@buffalo.edu>, svn-src-all@freebsd.org, avg@freebsd.org, gavin@freebsd.org, svn-src-head@freebsd.org, "M. Warner Losh" <imp@bsdimp.com> Subject: Re: svn commit: r212964 - head/sys/kern Message-ID: <20100928193611.GD2224@garage.freebsd.pl> In-Reply-To: <201009281504.12236.jhb@freebsd.org> References: <20100922222441.00002f27@unknown> <201009240923.04406.jhb@freebsd.org> <20100928183350.GB2224@garage.freebsd.pl> <201009281504.12236.jhb@freebsd.org>
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--0IvGJv3f9h+YhkrH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 28, 2010 at 03:04:11PM -0400, John Baldwin wrote: > > I am bigger fan of textdumps than minidumps, because in my opinion > > textdumps provide quite a lot of useful info. I'm working with FreeBSD > > kernel for years now and almost entirely avoided gdb for kernel > > debugging. DDB and printf(9) are in 99% enough for me (maybe I'm too > > traditional, but that's the fact). I'm not saying that textdumps are > > enough in 99%, though. >=20 > Have you looked at a /var/crash/core.txt.X file yet? If not, you should,= as > it is very similar to a text dump. In fact, it will contain the contents= of > any ddb trace buffer in addition to a stack trace from kgdb, process list= ing > from ps, etc. [...] > > Another important thing in my opinion is privacy of user's data. Once > > the data hit the disk it can stay there forever. This is why I use > > encrypted swap everywhere. I'd never send kernel minidump from my > > laptop or from any of my servers to anyone, but I'd be happy to send > > textdump. > >=20 > > I find textdumps a great solution that's in the middle between > > protecting user's privacy and providing a lot of useful info and I'd > > much prefer to turn on textdumps by default and eventually extend what > > we dump, than to make minidumps the default. >=20 > I'm suggesting they provide us the core.txt.X file, not the full minidump. > A developer could then ask them to run specific commands from a subsequent > kgdb session to obtain more details. But you still will have your kernel memory dumped to disk. This is probably not a problem for most of the users, though. > > You can always ask user to add this one-line to rc.conf to turn > > minidump on and provide you the info that was missing in textdump. >=20 > This only works for easily reproducible bugs, and in that case they can t= urn > on dumps later without a need for it to be automatic at all. And I'm arguing that those are very rare situations where there is a bug, which is hard to reproduce and where textdump won't be of any help. I'm aware that those are not strong arguments, but just worth taking into account, IMHO. --=20 Pawel Jakub Dawidek http://www.wheelsystems.com pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --0IvGJv3f9h+YhkrH Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkyiQ6sACgkQForvXbEpPzQghwCg1ez5WwJTA3HUe6ZVQ3nHWAfc qlkAn0dbFfmlVMg3e4qPTYkFi5pPn+6a =jCIE -----END PGP SIGNATURE----- --0IvGJv3f9h+YhkrH--
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