Last call for 3.0.0

[Mike Hommey]

On Thu, May 03, 2012 at 10:39:15AM -0700, Jason Evans wrote:
> On May 3, 2012, at 10:24 AM, Mike Hommey wrote:
> > On Wed, May 02, 2012 at 04:45:42PM -0700, Jason Evans wrote:
> >> On May 2, 2012, at 7:51 AM, Mike Hommey wrote:
> >>> I have to write 2 patches for MSVC-related issues that I'll send
> >>> later today.
> >> 
> >> I just committed all of your patches; thanks.
> >> 
> >>> I also get concerning (kind of) random (but not entirely so)
> >>> crashes in Firefox on Windows when using current jemalloc-dev. I
> >>> haven't narrowed down the problem yet, and probably won't until
> >>> tomorrow. It might be better to hold off a release until things
> >>> are cleared.
> >> 
> >> Some of my tests on Linux are crashing too; memset() within
> >> huge_ralloc() is causing a segfault, but I don't know whether the
> >> source or the destination is the problem, nor whether the bug is in
> >> jemalloc or the application (betting on jemalloc though).  Until
> >> that's resolved I won't be cutting a release.  Please let me know
> >> if you are able to further characterize the crashes you're seeing;
> >> they might be related to what I'm seeing.
> > 
> > It's rather strange that I get my crashes on Windows only.
> > Unfortunately, I can't reproduce locally, so debugging them will
> > have to wait for access to one of our test machines. Chances are
> > you'll have a patch for your issues before that, so I'll be able to
> > test if that fixes my issues.
> 
> I determined last night that the problem I'm hitting is due to a bad
> interaction between Linux kernel vma fragmentation (adjacent VM areas
> aren't being coalesced) and mremap(2).  This problem appears to be
> peculiar to Linux, so I doubt it's related to what you're seeing.
> Anyway, the fix/workaround may end up being rather involved, so I'm
> not optimistic about getting 3.0.0 released before next week.

So far, I haven't even been able to reproduce the issue on a machine I
have a shell on, which would allow better debugging. I tried enabling
debug on jemalloc in my firefox builds, and all that managed to produce
is trigger an assertion in arena.c:
 170         /* Freeing an unallocated pointer can cause assertion failure. */
 171         assert(bitmap_get(bitmap, &bin_info->bitmap_info, regind));

... the interesting part being that I'm still seeing the same crash as
the one I was originally getting, and *not* the assertion above when
running through our automated tests.

:(

Mike