On 05/24/2010 07:57 AM, Edgar E. Iglesias wrote: > I took a look at the code again and I dont really understand how the > particular case when we get a high address from the kernel while > mmap_min_addr is busy case is supposed to work :/ > In fact, for CRIS it never works on my host.
Indeed, there are many cases for which it doesn't work for the Alpha target either. > I changed it locally to keep scanning after a wrap until we succeed to > allocate a chunk or rewrap (SLOW) but at least I can run dynamically > linked CRIS programs again. Yep. My hack had been similar, except that I used the PageDesc tree to help speed things up. But PageDesc is hardly an ideal data structure in which to search, since it quickly devolves into a linear search of the address space. Probably the easiest real fix is to re-read /proc/self/maps each time the mmap_next_start guess fails and the kernel's returned address is out of range. Another is using the MMAP_32BIT flag on x86-64 host whenever a 31-bit address is appropriate for the guest. E.g. mips32, where architecturally the high half of the address space is reserved for kernel mode. See http://www.mail-archive.com/qemu-devel@nongnu.org/msg28924.html for more ideas on the subject. r~
