- 06 6月, 2008 6 次提交
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由 Rabin Vincent 提交于
Fix this warning, which appears with !CONFIG_SMP: kernel/sched.c:1216: warning: `init_hrtick' defined but not used Signed-off-by: NRabin Vincent <rabin@rab.in> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Dmitry Adamushko 提交于
Nothing really serious here, mainly just a matter of nit-picking :-/ From: Dmitry Adamushko <dmitry.adamushko@gmail.com> For CONFIG_SCHED_DEBUG && CONFIG_SYSCT configs, sd->flags can be altered while being manipulated in rebalance_domains(). Let's do an atomic check. We rely here on the atomicity of read/write accesses for aligned words. Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Gregory Haskins 提交于
The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: NGregory Haskins <ghaskins@novell.com> Acked-by: NSteven Rostedt <srostedt@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Mike Galbraith 提交于
it is safe to ignore timers and flags when the feature is disabled. Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Gregory Haskins 提交于
Dmitry Adamushko pointed out a known flaw in the rt-balancing algorithm that could allow suboptimal balancing if a non-migratable task gets queued behind a running migratable one. It is discussed in this thread: http://lkml.org/lkml/2008/4/22/296 This issue has been further exacerbated by a recent checkin to sched-devel (git-id 5eee63a5ebc19a870ac40055c0be49457f3a89a3). >From a pure priority standpoint, the run-queue is doing the "right" thing. Using Dmitry's nomenclature, if T0 is on cpu1 first, and T1 wakes up at equal or lower priority (affined only to cpu1) later, it *should* wait for T0 to finish. However, in reality that is likely suboptimal from a system perspective if there are other cores that could allow T0 and T1 to run concurrently. Since T1 can not migrate, the only choice for higher concurrency is to try to move T0. This is not something we addessed in the recent rt-balancing re-work. This patch tries to enhance the balancing algorithm by accomodating this scenario. It accomplishes this by incorporating the migratability of a task into its priority calculation. Within a numerical tsk->prio, a non-migratable task is logically higher than a migratable one. We maintain this by introducing a new per-priority queue (xqueue, or exclusive-queue) for holding non-migratable tasks. The scheduler will draw from the xqueue over the standard shared-queue (squeue) when available. There are several details for utilizing this properly. 1) During task-wake-up, we not only need to check if the priority preempts the current task, but we also need to check for this non-migratable condition. Therefore, if a non-migratable task wakes up and sees an equal priority migratable task already running, it will attempt to preempt it *if* there is a likelyhood that the current task will find an immediate home. 2) Tasks only get this non-migratable "priority boost" on wake-up. Any requeuing will result in the non-migratable task being queued to the end of the shared queue. This is an attempt to prevent the system from being completely unfair to migratable tasks during things like SCHED_RR timeslicing. I am sure this patch introduces potentially "odd" behavior if you concoct a scenario where a bunch of non-migratable threads could starve migratable ones given the right pattern. I am not yet convinced that this is a problem since we are talking about tasks of equal RT priority anyway, and there never is much in the way of guarantees against starvation under that scenario anyway. (e.g. you could come up with a similar scenario with a specific timing environment verses an affinity environment). I can be convinced otherwise, but for now I think this is "ok". Signed-off-by: NGregory Haskins <ghaskins@novell.com> CC: Dmitry Adamushko <dmitry.adamushko@gmail.com> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 29 5月, 2008 4 次提交
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由 Ingo Molnar 提交于
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: | 18d95a28 is first bad commit | commit 18d95a28 | Author: Peter Zijlstra <a.p.zijlstra@chello.nl> | 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: NYanmin Zhang <yanmin_zhang@linux.intel.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Roel Kluin 提交于
Removes obfuscation and may improve assembly. Signed-off-by: NRoel Kluin <roel.kluin@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
Yanmin Zhang reported: Comparing with kernel 2.6.25, sysbench+mysql(oltp, readonly) has many regressions with 2.6.26-rc1: 1) 8-core stoakley: 28%; 2) 16-core tigerton: 20%; 3) Itanium Montvale: 50%. Bisect located this patch: | 8f1bc385 is first bad commit | commit 8f1bc385 | Author: Peter Zijlstra <a.p.zijlstra@chello.nl> | Date: Sat Apr 19 19:45:00 2008 +0200 | | sched: fair: weight calculations Revert it to the 2.6.25 state. Bisected-by: NYanmin Zhang <yanmin_zhang@linux.intel.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 15 5月, 2008 1 次提交
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由 Mirco Tischler 提交于
Return type of cpu_rt_runtime_write() should be int instead of ssize_t. Signed-off-by: NMirco Tischler <mt-ml@gmx.de> Acked-by: NPaul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 5月, 2008 1 次提交
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由 Linus Torvalds 提交于
It acts exactly like a regular 'cond_resched()', but will not get optimized away when CONFIG_PREEMPT is set. Normal kernel code is already preemptable in the presense of CONFIG_PREEMPT, so cond_resched() is optimized away (see commit 02b67cc3 "sched: do not do cond_resched() when CONFIG_PREEMPT"). But when wanting to conditionally reschedule while holding a lock, you need to use "cond_sched_lock(lock)", and the new function is the BKL equivalent of that. Also make fs/locks.c use it. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 5月, 2008 1 次提交
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由 Linus Torvalds 提交于
The generic semaphore rewrite had a huge performance regression on AIM7 (and potentially other BKL-heavy benchmarks) because the generic semaphores had been rewritten to be simple to understand and fair. The latter, in particular, turns a semaphore-based BKL implementation into a mess of scheduling. The attempt to fix the performance regression failed miserably (see the previous commit 00b41ec2 'Revert "semaphore: fix"'), and so for now the simple and sane approach is to instead just go back to the old spinlock-based BKL implementation that never had any issues like this. This patch also has the advantage of being reported to fix the regression completely according to Yanmin Zhang, unlike the semaphore hack which still left a couple percentage point regression. As a spinlock, the BKL obviously has the potential to be a latency issue, but it's not really any different from any other spinlock in that respect. We do want to get rid of the BKL asap, but that has been the plan for several years. These days, the biggest users are in the tty layer (open/release in particular) and Alan holds out some hope: "tty release is probably a few months away from getting cured - I'm afraid it will almost certainly be the very last user of the BKL in tty to get fixed as it depends on everything else being sanely locked." so while we're not there yet, we do have a plan of action. Tested-by: NYanmin Zhang <yanmin_zhang@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Alexander Viro <viro@ftp.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 5月, 2008 10 次提交
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由 Peter Zijlstra 提交于
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: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
David Miller pointed it out that nothing in cpu_clock() sets prev_cpu_time. This caused __sync_cpu_clock() to be called all the time - against the intention of this code. The result was that in practice we hit a global spinlock every time cpu_clock() is called - which - even though cpu_clock() is used for tracing and debugging, is suboptimal. While at it, also: - move the irq disabling to the outest layer, this should make cpu_clock() warp-free when called with irqs enabled. - use long long instead of cycles_t - for platforms where cycles_t is 32-bit. Reported-by: NDavid Miller <davem@davemloft.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Miao Xie 提交于
When I echoed 0 into the "cpu.shares" file, a Div0 error occured. We found it is caused by the following calling. sched_group_set_shares(tg, shares) set_se_shares(tg->se[i], shares/nr_cpu_ids) __set_se_shares(se, shares) div64_64((1ULL<<32), shares) When the echoed value was less than the number of processores, the result of the sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide the result, the Div0 error occured. It is unnecessary that the shares value is divided by nr_cpu_ids, I think. Because in the function __update_group_shares_cpu() and init_tg_cfs_entry(), the shares value isn't divided by nr_cpu_ids when setting shares of the sched entity. This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also causes Div0 error, so we set a macro MAX_SHARES to limit the max value of shares. Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Heiko Carstens 提交于
Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
make time_sync_thresh tunable to architecture code. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 David Simner 提交于
http://bugzilla.kernel.org/show_bug.cgi?id=10545 sched_stats.h says that __sched_info_switch is "called when prev != next" in the comment. sched.c should therefore do that. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: NGautham R Shenoy <ego@in.ibm.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Harvey Harrison 提交于
Noticed by sparse: kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static? kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static? kernel/sched_fair.c:845:3: warning: returning void-valued expression kernel/sched.c:4386:3: warning: returning void-valued expression Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Andrew Morton 提交于
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: "Justin Mattock" <justinmattock@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Joel noticed that the !lw->inv_weight contition isn't unlikely anymore so remove the unlikely annotation. Also, remove the two div64_u64() inv_weight calculations, which makes them rely on the calc_delta_mine() path as well. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> CC: Joel Schopp <jschopp@austin.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 01 5月, 2008 1 次提交
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由 Roman Zippel 提交于
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: NRoman Zippel <zippel@linux-m68k.org> Cc: Avi Kivity <avi@qumranet.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 4月, 2008 2 次提交
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由 Paul Menage 提交于
This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: NPaul Menage <menage@google.com> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Paul Menage 提交于
Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: NPaul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 4月, 2008 4 次提交
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由 David Miller 提交于
There is no guarantee that there is physical ram below 4GB, and in fact many boxes don't have exactly that. Signed-off-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
fix __aggregate_redistribute_shares() related lockup reported by David S. Miller. The problem this code tries to solve is 'accurately' calculating the 'fair' share of the group weight for each cpu. The current code falls back to a global group rebalance in case the sched_domain's span it looks at has no shares, but does have tasks. The reason it gets stuck here, is because its inherently racy - if someone steals the last task after we compute the agg->rq_weight, but before we rebalance, we'll never get out of the loop. We could of course go fix that, but while looking at this issue I found that this 'fallback' wasn't nearly as rare as I'd hoped it to be. In fact its quite common - and given it walks the whole machine, thats very bad. The new approach is simple (why didn't I think of it before?), we set the aggregate shares to the full task group weight, and each larger sched domain that encounters an aggregate shares larger than the weight, clips it (it already re-distributes anyway). This nicely converges to the desired global picture where the sum of all shares equals the task group weight. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Travis 提交于
Regression caused by 434d53b0Signed-off-by: NMike Travis <travis@sgi.com> Signed-off-by: NTony Luck <tony.luck@intel.com>
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由 Russ Anderson 提交于
A recent change prevents SGI Altix from booting. This patch fixes the problem. The regresson was introduced in commit 434d53b0Signed-off-by: NRuss Anderson <rja@sgi.com> Signed-off-by: NTony Luck <tony.luck@intel.com>
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- 23 4月, 2008 1 次提交
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由 Randy Dunlap 提交于
Add missing kernel-doc in kernel/sched.c: Warning(linux-2.6.25-git3//kernel/sched.c:7044): No description found for parameter 'span' Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 4月, 2008 9 次提交
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由 Ingo Molnar 提交于
Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
unused at the moment. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
In order to level the hierarchy, we need to calculate load based on the root view. That is, each task's load is in the same unit. A / \ B 1 / \ 2 3 To compute 1's load we do: weight(1) -------------- rq_weight(A) To compute 2's load we do: weight(2) weight(B) ------------ * ----------- rq_weight(B) rw_weight(A) This yields load fractions in comparable units. The consequence is that it changes virtual time. We used to have: time_{i} vtime_{i} = ------------ weight_{i} vtime = \Sum vtime_{i} = time / rq_weight. But with the new way of load calculation we get that vtime equals time. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
De-couple load-balancing from the rb-trees, so that I can change their organization. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Implement SMP nice support for the full group hierarchy. On each load-balance action, compile a sched_domain wide view of the full task_group tree. We compute the domain wide view when walking down the hierarchy, and readjust the weights when walking back up. After collecting and readjusting the domain wide view, we try to balance the tasks within the task_groups. The current approach is a naively balance each task group until we've moved the targeted amount of load. Inspired by Srivatsa Vaddsgiri's previous code and Abhishek Chandra's H-SMP paper. XXX: there will be some numerical issues due to the limited nature of SCHED_LOAD_SCALE wrt to representing a task_groups influence on the total weight. When the tree is deep enough, or the task weight small enough, we'll run out of bits. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> CC: Abhishek Chandra <chandra@cs.umn.edu> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Hidetoshi Seto 提交于
[rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
multi level rt constraints Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Add the full parent<->child relation thing into task_groups as well. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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