Messages in this thread | | | From | Albert Cahalan <> | Subject | Re: possible SCSI device numbering solution | Date | Tue, 25 Jun 1996 19:22:38 -0400 (EDT) |
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From: koenig@tat.physik.uni-tuebingen.de (Harald Koenig) >> >> But anyhoot, 16/48 bit majors/minors seems reasonable to me. >> Of course, this is a blind guess - we really should discuss how >> majors/minors will be assigned and used first. We could easily gobble up >> 128-bits with a poor system, or, improve the current one and stick with >> 16-bits. > > any idea how the "ls -l" output should look like for larger dev_t ? > > crw-r----- 1 root kmem 1, 2 Aug 29 1992 /dev/kmem > brw-rw---- 1 root root 65535, 281474976710655 Apr 1 2001 /dev/last_dev_16_48 > brw-rw---- 1 root root 4294967295, 4294967295 Apr 1 2001 /dev/last_dev_32_32 > brw-rw---- 1 root disk 8, 0 May 4 1994 /dev/sda > > doesn't look too nice ;-)
------------------ For 64-bit device numbers -------------------
Here's the old way: brw-rw---- 1 root disk 8, 0 May 4 1994 /dev/sda
Hex won't quite fit: brw-rw---- 1 root disk 2847a3b5f9e310f9 May 4 1994 /dev/sda
Use base-64 encoding: brw-rw---- 1 root disk 3Aib31fzeTc May 4 1994 /dev/sda
------------------- For something that fits --------------------
If we only use 48 bits (dev_t is padded to 64-bit) then hex will fit in the display correctly: brw-rw---- 1 root disk a3b5f9e310f9 May 4 1994 /dev/sda
Break up device numbers on nibble boundries for readability.
controller:4 bus:4 device:8 lun:8 partition:4
Hmmm, that is only 28 bits. Did I miss something? If SCSI, IDE, and all the weird stuff gets unified naming, then 36 bits are left over! Even with 8-bit partition numbers, 32 bits is enough.
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