on 12/12/2012 19:06 Adrian Chadd said the following: > kassert()s are already optional. Ie, you can choose to not compile them in. > > So the __dead2() code path bit for doing KASSERT() -> kassert_panic() > at compile time isn't a problem. > > The problem is where you do panic() -> kassert_panic() (eg in the > Witness code) which is what Alfred discovered shortly after doing up > his initial patch. > > Anything which is a KASSERT() can and should be treated as a run-time > warning just as much as a run-time "crash here so I can figure out > what broke." Having the warning in a production box is going to be > helpful for developers.
I have a quite different view on purpose and costs of KASSERTs. Specifically referring to r243980 I do not think that "non-fatal asserts" should really exist (or do exist). I wish all this muddying of KASSERT meaning would get reverted. These quite sensitive changes were rushed in, IMO. > On 12 December 2012 07:46, John Baldwin <j...@freebsd.org> wrote: >> On Tuesday, December 11, 2012 2:08:14 am Alfred Perlstein wrote: >>> Author: alfred >>> Date: Tue Dec 11 07:08:14 2012 >>> New Revision: 244112 >>> URL: http://svnweb.freebsd.org/changeset/base/244112 >>> >>> Log: >>> Cleanup more of the kassert_panic. >>> >>> fix compile warnings on !amd64 and NULL derefs that would happen >>> if kassert_panic() would return. >> >> This is one reason why having kassert not panic is such a bad idea. There >> are >> tons of places where the compiler knows that panic() is __dead2, and there is >> no cleanup code to handle what happens when an invariant is violated. This >> is >> not safe to run in the field unless your customers do not care about their >> data. If you are interested in doing regression tests, I am using a very >> different approach for some locking regression tests I am working on in p4 >> that allow you to use a wrapper around setjmp/longjmp to "catch" panics >> somewhat like exception handling in C++/Java (though much cruder). However, >> evne that is only intended for testing, not for production cases where >> production data is at stake. >> >> -- >> John Baldwin -- Andriy Gapon -- Andriy Gapon _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
