linux/kernel/sched_debug.c, branch v2.6.28

sched: fix kernel warning on /proc/sched_debug access

2008-11-16T07:07:15Z

Luis Henriques reported that with CONFIG_PREEMPT=y + CONFIG_PREEMPT_DEBUG=y + CONFIG_SCHED_DEBUG=y + CONFIG_LATENCYTOP=y enabled, the following warning triggers when using latencytop: > [ 775.663239] BUG: using smp_processor_id() in preemptible [00000000] code: latencytop/6585 > [ 775.663303] caller is native_sched_clock+0x3a/0x80 > [ 775.663314] Pid: 6585, comm: latencytop Tainted: G W 2.6.28-rc4-00355-g9c7c354 #1 > [ 775.663322] Call Trace: > [ 775.663343] [] debug_smp_processor_id+0xe4/0xf0 > [ 775.663356] [] native_sched_clock+0x3a/0x80 > [ 775.663368] [] sched_clock+0x9/0x10 > [ 775.663381] [] proc_sched_show_task+0x8bd/0x10e0 > [ 775.663395] [] sched_show+0x3e/0x80 > [ 775.663408] [] seq_read+0xdb/0x350 > [ 775.663421] [] ? security_file_permission+0x16/0x20 > [ 775.663435] [] vfs_read+0xc8/0x170 > [ 775.663447] [] sys_read+0x55/0x90 > [ 775.663460] [] system_call_fastpath+0x16/0x1b > ... This breakage was caused by me via: 7cbaef9: sched: optimize sched_clock() a bit Change the calls to cpu_clock(). Reported-by: Luis Henriques

sched: clean up debug info

2008-11-10T09:51:51Z

Impact: clean up and fix debug info printout While looking over the sched_debug code I noticed that we printed the rq schedstats for every cfs_rq, ammend this. Also change nr_spead_over into an int, and fix a little buglet in min_vruntime printing. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

sched: change sched_debug's mode to 0444

2008-10-30T10:37:57Z

Impact: change /proc/sched/debug from rw-r--r-- to r--r--r-- /proc/sched_debug is read-only. Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar

[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()

2008-10-10T00:18:57Z

lock_task_sighand() make sure task->sighand is being protected, so we do not need rcu_read_lock(). [ exec() will get task->sighand->siglock before change task->sighand! ] But code using rcu_read_lock() _just_ to protect lock_task_sighand() only appear in procfs. (and some code in procfs use lock_task_sighand() without such redundant protection.) Other subsystem may put lock_task_sighand() into rcu_read_lock() critical region, but these rcu_read_lock() are used for protecting "for_each_process()", "find_task_by_vpid()" etc. , not for protecting lock_task_sighand(). Signed-off-by: Lai Jiangshan [ok from Oleg] Signed-off-by: Alexey Dobriyan

sched: add full schedstats to /proc/sched_debug

2008-06-27T12:31:31Z

show all the schedstats in /debug/sched_debug as well. Signed-off-by: Peter Zijlstra Cc: Srivatsa Vaddagiri Cc: Mike Galbraith Signed-off-by: Ingo Molnar

sched: revert revert of: fair-group: SMP-nice for group scheduling

2008-06-27T12:31:29Z

Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra Cc: Srivatsa Vaddagiri Cc: Mike Galbraith Signed-off-by: Ingo Molnar

sched: debug: add some rt debug output

2008-06-20T08:25:59Z

Signed-off-by: Peter Zijlstra Cc: "Daniel K." Signed-off-by: Ingo Molnar

revert ("sched: fair-group: SMP-nice for group scheduling")

2008-05-29T09:28:57Z

Yanmin Zhang reported: Comparing with 2.6.25, volanoMark has big regression with kernel 2.6.26-rc1. It's about 50% on my 8-core stoakley, 16-core tigerton, and Itanium Montecito. With bisect, I located the following patch: | 18d95a2832c1392a2d63227a7a6d433cb9f2037e is first bad commit | commit 18d95a2832c1392a2d63227a7a6d433cb9f2037e | Author: Peter Zijlstra | Date: Sat Apr 19 19:45:00 2008 +0200 | | sched: fair-group: SMP-nice for group scheduling Revert it so that we get v2.6.25 behavior. Bisected-by: Yanmin Zhang Signed-off-by: Ingo Molnar

sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK

2008-05-05T21:56:18Z

this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

rename div64_64 to div64_u64

2008-05-01T15:03:58Z

Rename div64_64 to div64_u64 to make it consistent with the other divide functions, so it clearly includes the type of the divide. Move its definition to math64.h as currently no architecture overrides the generic implementation. They can still override it of course, but the duplicated declarations are avoided. Signed-off-by: Roman Zippel Cc: Avi Kivity Cc: Russell King Cc: Geert Uytterhoeven Cc: Ralf Baechle Cc: David Howells Cc: Jeff Dike Cc: Ingo Molnar Cc: "David S. Miller" Cc: Patrick McHardy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds