AMD64 Linux -- Strange Virtual Mem Mapping...

I have RH3.0 installed in an AMD64 machine.

In this system, when I look at the virtual address space mappings of a process (say a sleep process), I see quite a few strange memory region mappings which are neither readable, nor writable/executable and all of them are Private (i.e. unshared). Check this:

1024 ---p /lib64/tls/libc-2.3.2.so

1024 ---p /lib64/tls/libm-2.3.2.so

1024 ---p /lib64/tls/librtkaio-2.3.2.so

1024 ---p /lib64/tls/libpthread-0.60.so

On the other hand, when I look at the same info in a Rh7.2 system, I don't see anything like that...

Question: How do I make sense of an unreadable/unwritable/unexecutable privately mapped memory region? What is its usage? It looks like a 100% wastage of the process's address space. How is the process using it? Any idea...anybody?

You can find the sample "sleep" commands below.

vgamd126:arijit>sleep 400 &
[1] 19916

vgamd126:arijit>pmap 19916
Size (KB)    Perm    Associated files (if any)
==========    ====    =============================================
        16    r-xp    /bin/sleep
         4    rw-p    /bin/sleep
       132    rwxp
      1108    r-xp    /lib64/ld-2.3.2.so
         4    rw-p    /lib64/ld-2.3.2.so
         4    rw-p
       540    r-xp    /lib64/tls/libm-2.3.2.so
      1024    ---p    /lib64/tls/libm-2.3.2.so
         4    rw-p    /lib64/tls/libm-2.3.2.so
         4    rw-p
        36    r-xp    /lib64/tls/librtkaio-2.3.2.so
      1024    ---p    /lib64/tls/librtkaio-2.3.2.so
         4    rw-p    /lib64/tls/librtkaio-2.3.2.so
        64    rw-p
      1260    r-xp    /lib64/tls/libc-2.3.2.so
      1024    ---p    /lib64/tls/libc-2.3.2.so
        20    rw-p    /lib64/tls/libc-2.3.2.so
        16    rw-p
        60    r-xp    /lib64/tls/libpthread-0.60.so
      1024    ---p    /lib64/tls/libpthread-0.60.so
         4    rw-p    /lib64/tls/libpthread-0.60.so
        20    rw-p
     31396    r--p    /usr/lib/locale/locale-archive
        24    rw-p

Total Virtual Memory = 38816 KB
vgamd126:arijit>

eurika120:arijit>sleep 400 &
[1] 11065

eurika120:arijit>pmap 11065
Size (KB)    Perm    Associated files (if any)
==========    ====    =============================================
        12    r-xp    /bin/sleep
         4    rw-p    /bin/sleep
         8    rwxp
        88    r-xp    /lib/ld-2.2.4.so
         4    rw-p    /lib/ld-2.2.4.so
         4    r--p    /usr/lib/locale/en_US/LC_IDENTIFICATION
         4    r--p    /usr/lib/locale/en_US/LC_MEASUREMENT
         4    r--p    /usr/lib/locale/en_US/LC_TELEPHONE
         4    r--p    /usr/lib/locale/en_US/LC_ADDRESS
         4    r--p    /usr/lib/locale/en_US/LC_NAME
         4    r--p    /usr/lib/locale/en_US/LC_PAPER
         4    r--p    /usr/lib/locale/en_US/LC_MESSAGES/SYS_LC_MESSAGES
         4    r--p    /usr/lib/locale/en_US/LC_MONETARY
        24    r--p    /usr/lib/locale/en_US/LC_COLLATE
         4    r--p    /usr/lib/locale/en_US/LC_TIME
         4    r--p    /usr/lib/locale/en_US/LC_NUMERIC
         4    rw-p
       136    r-xp    /lib/i686/libm-2.2.4.so
         4    rw-p    /lib/i686/libm-2.2.4.so
        28    r-xp    /lib/librt-2.2.4.so
         4    rw-p    /lib/librt-2.2.4.so
        40    rw-p
      1224    r-xp    /lib/i686/libc-2.2.4.so
        20    rw-p    /lib/i686/libc-2.2.4.so
        16    rw-p
        52    r-xp    /lib/i686/libpthread-0.9.so
        32    rw-p    /lib/i686/libpthread-0.9.so
       172    r--p    /usr/lib/locale/en_US/LC_CTYPE
        24    rwxp

Total Virtual Memory = 1936 KB
eurika120:arijit>