Hello.. On Jan 18, 2008 1:35 AM, Vince Weaver <[EMAIL PROTECTED]> wrote: > Hello > > The 0.9.1 release segfaults on certain benchmarks under linux-user > emulation (x86 on x86). > > Specifically "facerec" from the SPEC2000 benchmarks, and over half of the > SPEC2006 benchmarks. > > I tracked this down to a problem in the mmap() code in linux-user. > > I've attached a patch that reverts behavior back to that from 0.9.0, which > makes the benchmarks all run for me. > > The problem is that after a large number of mmap() calls, the > mmap_find_vma() fuction sometimes completely destroys the memory map > table. I can produce debug info on this if needed. What the patch does > is make the code ignore the results of mmap_find_vma(). > > I'm not familiar enough with the qemu mmap() code to fix this properly... > > Thanks > > Vince > > --- ./qemu-0.9.1-stock/linux-user/mmap.c 2008-01-06 14:38:42.000000000 > -0500 > +++ ./qemu-0.9.1/linux-user/mmap.c 2008-01-17 13:27:11.000000000 -0500 > @@ -250,8 +250,8 @@ > /* Note: we prefer to control the mapping address. It is > especially important if qemu_host_page_size > > qemu_real_host_page_size */ > - p = mmap(g2h(mmap_start), > - host_len, prot, flags | MAP_FIXED, fd, host_offset); > + p = mmap(real_start ? g2h(real_start) : NULL, > + host_len, prot, flags, fd, host_offset);
urmmm, sure we need to throw out MAP_FIXED flag? sounds like from the upper "Notes", it's need to control the start address of mapped VMA..in the case of must-on-real_start. CMIIW too..just dumb static code analysis. regards, Mulyadi.
