2.6.12

• Released June 17, 2005 changelog

• Pageout throttling: With silly pageout testcases it is possible to place huge amounts of memory under I/O. With a large request queue (CFQ uses 8192 requests) it is possible to place _all_ memory under I/O at the same time. This means that all memory is pinned and unreclaimable and the VM gets upset and goes oom. This patch limits the amount of memory which is under pageout writeout to be a little more than the amount of memory at which balance_dirty_pages() callers will synchronously throttle. This means that heavy pageout activity can starve heavy writeback activity completely, but heavy writeback activity will not cause starvation of pageout (commit)

• Address space randomization: With these patches applied, each process's stack will begin at a random location, and the beginning of the memory area used for mmap() (which is where shared libraries go, among other things) will be randomized as well (LWN article) (commit) - (commit) - (commit) - (commit) - (commit) - (commit) - (commit) - (commit)

• Cpusets (LWN article) (commit)

• "resource limits": RLIMIT_NICE and RLIMIT_RTPRIO added to allow non-root tasks to raise nice and rt priorities. Defaults to traditional behavior (LWN article) (commit)

• Multilevel security implementation for SELinux

• Seccomp security mechanism (commit)

• Support for Cyrix MediaGX (aka GEODE) CPUs. Linux and GCC treat this chip as a 586TSC with some extended instructions and alignment reqirements (commit)

• I/O barrier support for serial ATA drives
• Block I/O barrier rewrite (enables full barrier support on serial ATA drives)

• Annotate /proc/$PID/maps with [heap]/[stack]/[vdso] markers (commit)

• SuperHyway bus support

• Device mapper multipath support (LWN article)

• Hot-pluggable parallel ports (commit)

• Updated FAT attributes: This updates the FAT attributes as well as corrects the handling of VFAT ctime (commit)

• Handle MS_SYNCHRONOUS flag in FAT: FAT filesystem has been ignoring the "sync" mount option for ages. This patches fixes this, but (obviously) degrades performance unless you mount your FAT filesystem as asynchronous ("async mount option) (commit)

• Add timing information to printk messages (commit)

• Allow admin to enable only some of the Magic-Sysrq functions (commit)

• Loglevel boot option (commit)

• Remove IPV6 "experimental" status