This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: PCH support on Solaris
> Do you mean that this code under Solaris
>
> size = 1048576
> guess = mmap (NULL, size, PROT_NONE,
> MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
> munmap (guess, size);
> addr = mmap (guess+4096, size-4096, PROT_NONE,
> MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
> printf ("%x %x\n", guess, addr);
>
> gives the same address for both guess and size? That is, that Solaris
> completely ignores the first argument unless MAP_FIXED is given?
It appears so, indeed.
> If so, my idea is useless at least under Solaris. But if not, I don't see
> your point.
No, it is not useless under Solaris, since
guess = mmap (NULL, size, PROT_NONE, MAP_PRIVATE, fd, 0);
munmap (guess, size);
addr = mmap (guess, size-4096, PROT_READ, MAP_PRIVATE, fd, 4096);
printf ("%x %x\n", guess, addr);
doesn't return the same address.
--
Eric Botcazou