Re: Patch ping

[Richard Biener <rguenther at suse dot de>]

On Tue, 5 Mar 2013, Jakub Jelinek wrote:

> On Tue, Mar 05, 2013 at 02:26:03PM +0100, Richard Biener wrote:
> > On Tue, 5 Mar 2013, Jakub Jelinek wrote:
> > > Thanks for all the recent reviews of memory leak plugging patches,
> > > there are 4 still unreviewed from last week though.
> > > 
> > > - sched-deps leak fix:
> > > http://gcc.gnu.org/ml/gcc-patches/2013-02/msg01197.html
> > > 
> > > - LRA leak fix:
> > > http://gcc.gnu.org/ml/gcc-patches/2013-02/msg01239.html
> > > 
> > > - libcpp leak fix:
> > > http://gcc.gnu.org/ml/gcc-patches/2013-02/msg01341.html
> > > 
> > > - PCH leak fix + --enable-checking=valgrind changes to allow
> > >   --enable-checking=yes,valgrind bootstrap to succeed:
> > > http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00044.html
> > 
> > That looks awkward ... isn't there a simple valgrind_disable () /
> > valgrind_enable () way of disabling checking around this code?
> 
> Unfortunately not.  I went through all valgrind.h and memcheck.h
> client calls.  If at least there was a VALGRIND_GET_VBITS variants
> that allowed getting all vbits, (i.e. whether something is unaddressable
> vs. undefined vs. defined), rather than just if any of the vbits are
> unaddressable, give up, otherwise return undefined vs. defined bits,
> it would simplify the code.  I hope perhaps future valgrind version
> could add that, so it would be just VALGRIND_GET_VBITS2,
> VALGRIND_MAKE_MEM_DEFINED before and VALGRIND_SET_VBITS2 at the end
> (restore previous state).  I've at least added __builtin_expect,
> so the binary search code isn't in hot path.  It isn't that slow,
> during binary search I'm always testing just a single byte, and
> say if we don't have any single memory allocations > 4GB, it will be
> at most 37 valgrind client calls per objects, usually much smaller
> number than that.

Alternatively using a suppressions file during bootstrap might
be possible ... maybe also useful for general valgrind
debugging use?

Richard.