You mean between RHEL 4 U5 and RHEL 5 U2. I'd say the major release versions are different enough in kernel architecture (2.6.9-something vs 2.6.18) and userland improvement to make up for that. I don't run 4 so on the left hand side is Centos-3, right is Centos-5. You see the process on 5 is leaner:
Code:
Virtual memory size: 4096 KB | Virtual memory size: 3708 KB
Resident set size: 484 KB | Resident set size: 460 KB
Current real memory limit: 4194303 KB Current real memory limit: 4194303 KB
Code segment: 0x08048000 - 0x0804ab44 (10 KB) | Code segment: 0x08048000 - 0x0804bb18 (14 KB)
Data segment size: 448 KB | Data segment size: 156 KB
Stack size: 8 KB | Stack size: 84 KB
Library segment size: 1536 KB | Library segment size: 1376 KB
Currently mapped memory regions: Currently mapped memory regions:
Address Perm Offset Dev Inode Address Perm Offset Dev Inode
------------------------------------------------ ------------------------------------------------
08048000-0804b000 r-xp 00000000 03:07 46953 /bin/slee | 0049b000-0049c000 r-xp 0049b000 00:00 0 [vdso]
0804b000-0804d000 rw-p 00002000 03:07 46953 /bin/slee | 0051a000-00534000 r-xp 00000000 08:03 159725 /lib/ld-2
0804d000-0806e000 rwxp 00000000 00:00 0 | 00534000-00535000 r-xp 00019000 08:03 159725 /lib/ld-2
40006000-40007000 rw-p 00000000 00:00 0 | 00535000-00536000 rwxp 0001a000 08:03 159725 /lib/ld-2
40007000-40207000 r--p 00000000 03:05 32293 /usr/lib/ | 00538000-00676000 r-xp 00000000 08:03 159729 /lib/libc
4a457000-4a46c000 r-xp 00000000 03:07 42889 /lib/ld-2 | 00676000-00678000 r-xp 0013e000 08:03 159729 /lib/libc
4a46c000-4a46d000 rw-p 00015000 03:07 42889 /lib/ld-2 | 00678000-00679000 rwxp 00140000 08:03 159729 /lib/libc
4a46f000-4a5a3000 r-xp 00000000 03:07 12447 /lib/i686 | 00679000-0067c000 rwxp 00679000 00:00 0
4a5a3000-4a5a6000 rw-p 00134000 03:07 12447 /lib/i686 | 08048000-0804c000 r-xp 00000000 08:03 191439 /bin/slee
4a5a6000-4a5a9000 rw-p 00000000 00:00 0 | 0804c000-0804e000 rw-p 00003000 08:03 191439 /bin/slee
4a5d4000-4a5f5000 r-xp 00000000 03:07 12449 /lib/i686 | 09820000-09841000 rw-p 09820000 00:00 0 [heap]
4a5f5000-4a5f6000 rw-p 00021000 03:07 12449 /lib/i686 | b7d5a000-b7f5a000 r--p 00000000 08:05 165953 /usr/lib/
4a670000-4a67e000 r-xp 00000000 03:07 12448 /lib/i686 | b7f5a000-b7f5c000 rw-p b7f5a000 00:00 0
4a67e000-4a681000 rw-p 0000e000 03:07 12448 /lib/i686 | bfa41000-bfa56000 rw-p bffea000 00:00 0 [stack]
4a681000-4a6c1000 rw-p 00000000 00:00 0 | Used stack: 0xbfa54b68 - 0xbfa54cc0 (344 bytes) [esp == 0xbfa
4a849000-4a851000 r-xp 00000000 03:07 12450 /lib/i686 | Current instruction is at: 0x0049b402
4a851000-4a852000 rw-p 00007000 03:07 12450 /lib/i686 <
4a852000-4a85d000 rw-p 00000000 00:00 0 <
bfffe000-c0000000 rwxp fffff000 00:00 0 <
Used stack: 0xbffff8ec - 0xbffffa00 (276 bytes) [esp == 0xbff <
Current instruction is at: 0x4a51a245 <