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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2007-02-16 01:28:22 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-16 08:14:00 -0800
commit1f2ea0837dbc263ce2a2512c4e73c83df68a6a55 (patch)
tree8e033c747852671f3d4d2cb0bc677dab9ecfc441 /arch/i386
parent7460ed2844ffad7141e30271c0c3da8336e66014 (diff)
[PATCH] posix timers: RCU optimization for clock_gettime()
Use RCU to avoid the need to acquire tasklist_lock in the single-threaded case of clock_gettime(). It still acquires tasklist_lock when for a (potentially multithreaded) process. This change allows realtime applications to frequently monitor CPU consumption of individual tasks, as requested (and now deployed) by some off-list users. This has been in Ingo Molnar's -rt patchset since late 2005 with no problems reported, and tests successfully on 2.6.20-rc6, so I believe that it is long-since ready for mainline adoption. [paulmck@linux.vnet.ibm.com: fix exit()/posix_cpu_clock_get() race spotted by Oleg] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/i386')
0 files changed, 0 insertions, 0 deletions