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Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
@Jim B, What section do you refer in manual vol1 ? 9.2 of "optimization" says directly: "Assembly/Compiler Coding Rule 65. (H impact, M generality) Use the 32-bit versions of instructions in 64-bit mode to reduce code size unless the 64-bit version is necessary to access 64-bit data or additional registers. " .. "but the 32-bit version saves one instruction byte:" (REX prefix). Also from 3.2 section of "optimization": Instruction decode throughput is important for processors based on Intel Core i7 processors, Intel Core microarchitecture
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
Hmm. Do you install entire 32-bit os? Can you use gcc for 64-bit mode? Is there 64 and 32 bit libc for large programs which must be 64bit, like multi-gb database?
Feb
6
revised Which OS/distributions have 64-bit kernel and 32-bit userspace?
must->can for database
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
@phoebus - And you greatly underestimate negative impact of 64-bit programs. Every pointer in 64 have a unneeded extra 32 bit. They are really unused. @Jim B, In case of x86_64 - 64bit code requires more prefixes and more decoding, than 32 bit. Can you give me a link to article describing slow speed of 32bit code on 64?
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
In linux and many other unixes there is a mmap64 system call to using >4 GB mmaped files. Yes, such files can't be mmaped entire file at once, but THERE ARE a little number of programs which really needs such files to be mmaped. "cat", "dd", "bash", even "gcc" does not have to be 64-bit.
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
64bit pointer is wasting of memory, of cache lines, of memory bandwidth. It is overkill, because only 40-50 bits of memory addressing is really implemented in hardware, and because I don't allow each program to use >=3-4 GB of RAM. I want allow computer (and OS) to have >=3-4GB of RAM and use 64bit mode for selected applications.
Feb
6
revised Which OS/distributions have 64-bit kernel and 32-bit userspace?
added 328 characters in body
Feb
6
answered How to synchronize users, passwords, hosts, etc without NIS
Feb
6
comment Kernel level IP configuration not working in Linux kernel
Also, you need to check kernel logs: KERN_NOTICE level for "Sending ... requests" where ... can be DHCP, BOOTP, RARP
Feb
6
awarded  Commentator
Feb
6
comment Kernel level IP configuration not working in Linux kernel
config IP_PNP_DHCP bool "IP: DHCP support" depends on IP_PNP lxr.linux.no/#linux+v2.6.19/net/ipv4/Kconfig
Feb
6
comment Kernel level IP configuration not working in Linux kernel
Does you turn on CONFIG_IP_PNP_DHCP ?
Feb
6
answered Kernel level IP configuration not working in Linux kernel
Feb
6
answered Two SSL certificates with same key
Feb
6
comment What's the difference between 301 and 302 in HTTP?
+ stackoverflow.com/questions/1393280/…
Feb
6
answered What's the difference between 301 and 302 in HTTP?
Feb
6
revised Which OS/distributions have 64-bit kernel and 32-bit userspace?
added 154 characters in body
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
There are some OS with such 32/64 bit separation and I want to get a list of such OS.
Feb
6
comment Which OS/distributions have 64-bit kernel and 32-bit userspace?
64-bit code is bigger than 32-bit. 64bit mode really needed by a very little number of programmes
Feb
6
asked Which OS/distributions have 64-bit kernel and 32-bit userspace?