mlockall() on freebsd 7.2 + amd64 returns EAGAIN

[Sushanth Rai]

I've attached the simple program that creates 5 threads. Following is the o/p of /proc/<pid>/map when this program is running. Note that I modified 
sys/fs/procfs/procfs_map.c to print whether a region is wired. As you can see from this o/p, none of stack areas get wired. 

0x400000 0x401000 1 0 0xffffff002d943bd0 r-x 1 0 0x1000 COW NC wired vnode /var/tmp/thread1
0x500000 0x501000 1 0 0xffffff002dd13e58 rw- 2 0 0x3100 NCOW NNC wired default -
0x501000 0x600000 255 0 0xffffff002dd13e58 rwx 2 0 0x3100 NCOW NNC wired default -
0x800500000 0x800526000 38 0 0xffffff0025574000 r-x 192 46 0x1004 COW NC wired vnode /libexec/ld-elf.so.1
0x800526000 0x800537000 17 0 0xffffff002d9f81b0 rw- 1 0 0x3100 NCOW NNC wired default -
0x800626000 0x80062d000 7 0 0xffffff002dd13bd0 rw- 1 0 0x3100 COW NNC wired vnode /libexec/ld-elf.so.1
0x80062d000 0x800633000 6 0 0xffffff002dd145e8 rw- 1 0 0x3100 NCOW NNC wired default -
0x800633000 0x800645000 18 0 0xffffff00256d71b0 r-x 63 42 0x4 COW NC wired vnode /lib/libthr.so.3
0x800645000 0x800646000 1 0 0xffffff002d975510 r-x 1 0 0x3100 COW NNC wired vnode /lib/libthr.so.3
0x800646000 0x800746000 0 0 0xffffff002dc5cca8 --- 4 0 0x3100 NCOW NNC not-wired default -
0x800746000 0x80074a000 4 0 0xffffff002572a288 rw- 1 0 0x3100 COW NNC wired vnode /lib/libthr.so.3
0x80074a000 0x80074c000 2 0 0xffffff002dc5cca8 rw- 4 0 0x3100 NCOW NNC wired default -
0x80074c000 0x80083e000 242 0 0xffffff001cd226c0 r-x 238 92 0x1004 COW NC wired vnode /lib/libc.so.7
0x80083e000 0x80083f000 1 0 0xffffff002dd12000 r-x 1 0 0x3100 COW NNC wired vnode /lib/libc.so.7
0x80083f000 0x80093e000 0 0 0xffffff002dc5cca8 --- 4 0 0x3100 NCOW NNC not-wired default -
0x80093e000 0x80095d000 31 0 0xffffff002dddc360 rw- 1 0 0x3100 COW NNC wired vnode /lib/libc.so.7
0x80095d000 0x800974000 23 0 0xffffff002dc5cca8 rw- 4 0 0x3100 NCOW NNC wired default -
0x800a00000 0x800b00000 256 0 0xffffff002dbd1798 rw- 1 0 0x3100 NCOW NNC wired default -
0x800b00000 0x800c00000 256 0 0xffffff002dd14948 rw- 1 0 0x3100 NCOW NNC wired default -
0x7fffff3db000 0x7fffff3fb000 1 0 0xffffff002dbb4360 rw- 1 0 0x3100 NCOW NNC not-wired default -
0x7fffff5dc000 0x7fffff5fc000 1 0 0xffffff002dc66af8 rw- 1 0 0x3100 NCOW NNC not-wired default -
0x7fffff7dd000 0x7fffff7fd000 1 0 0xffffff002dbea438 rw- 1 0 0x3100 NCOW NNC not-wired default -
0x7fffff9de000 0x7fffff9fe000 1 0 0xffffff002dd7fd80 rw- 1 0 0x3100 NCOW NNC not-wired default -
0x7fffffbdf000 0x7fffffbff000 1 0 0xffffff002dbe9438 rw- 1 0 0x3100 NCOW NNC not-wired default -
0x7fffffbff000 0x7fffffc00000 0 0 0 --- 0 0 0x0 NCOW NNC not-wired none -
0x7ffffffe0000 0x800000000000 32 0 0xffffff002dd125e8 rwx 1 0 0x3100 NCOW NNC wired default -

--- On Fri, 4/13/12, Konstantin Belousov <kostikbel at gmail.com> wrote:

> From: Konstantin Belousov <kostikbel at gmail.com>
> Subject: Re: mlockall() on freebsd 7.2 + amd64 returns EAGAIN
> To: "Sushanth Rai" <sushanth_rai at yahoo.com>
> Cc: freebsd-hackers at freebsd.org
> Date: Friday, April 13, 2012, 1:11 AM
> On Thu, Apr 12, 2012 at 08:10:26PM
> -0700, Sushanth Rai wrote:
> > > 
> > > Then it should be fixed in r190885.
> > > 
> > 
> > Thanks. That works like a charm. 
> > 
> > mlockall() mostly works now. There is still a, issue in
> wiring the stacks of multithreaded program when the program
> uses default stack allocation scheme. Thread library
> allocates stack for each thread by calling mmap() and
> sending address and size to be mapped. The kernel adjusts
> the start address to sgrowsz in  vm_map_stack() and
> maps at the adjusted address. But the subsequent wiring is
> done using the original address, which fails. 
> > 
> Can you, please provide stand-alone example which
> demostrates the issue ?
> I suspect this should have not changed in HEAD.
>