- 16 11月, 2009 1 次提交
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由 Peter Zijlstra 提交于
The purpose of perf_output_{un,}lock() is to: 1) avoid publishing incomplete data [ possible when publishing a head that is ahead of an entry that is still being written ] 2) guarantee fwd progress [ a simple refcount on pending writers doesn't need to drop to 0, making it so would end up implementing something like forced quiecent states of RCU ] To satisfy the above without undue complexity it serializes between CPUs, this means that a pending writer can only be the same cpu in a nested context, and since (under normal operation) a cpu always makes progress we're good -- if the head is only published when the bottom most writer completes. Now we don't need to disable IRQs in order to serialize between CPUs, disabling preemption ought to be sufficient, esp since we already deal with nesting due to NMIs. This avoids potentially expensive (and needless) local IRQ disable/enable ops. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1258373161.26714.254.camel@laptop> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 13 11月, 2009 1 次提交
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由 Frederic Weisbecker 提交于
Lockdep events subsystem gathers various locking related events such as a request, release, contention or acquisition of a lock. The name of this event subsystem is a bit of a misnomer since these events are not quite related to lockdep but more generally to locking, ie: these events are not reporting lock dependencies or possible deadlock scenario but pure locking events. Hence this rename. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Acked-by: NHitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <1258103194-843-1-git-send-email-fweisbec@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 10 11月, 2009 2 次提交
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由 Frederic Weisbecker 提交于
The hw-breakpoint sample module has been broken during the hw-breakpoint internals refactoring. Propagate the changes to it. Reported-by: N"K. Prasad" <prasad@linux.vnet.ibm.com> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
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由 Paul Mundt 提交于
All of the infrastructure already exists to support read accesses for platforms that support a read access independently of read/write (such as in the case of the SuperH UBC). This just trivially hooks up the read case by itself. Signed-off-by: NPaul Mundt <lethal@linux-sh.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20091109083733.GA25848@linux-sh.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
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- 08 11月, 2009 7 次提交
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由 Li Zefan 提交于
The macro used to be used in both trace_selftest.c and trace_ksym.c, but no longer, so remove it from header file. Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
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由 Frederic Weisbecker 提交于
Allow or refuse to build a counter using the breakpoints pmu following given constraints. We keep track of the pmu users by using three per cpu variables: - nr_cpu_bp_pinned stores the number of pinned cpu breakpoints counters in the given cpu - nr_bp_flexible stores the number of non-pinned breakpoints counters in the given cpu. - task_bp_pinned stores the number of pinned task breakpoints in a cpu The latter is not a simple counter but gathers the number of tasks that have n pinned breakpoints. Considering HBP_NUM the number of available breakpoint address registers: task_bp_pinned[0] is the number of tasks having 1 breakpoint task_bp_pinned[1] is the number of tasks having 2 breakpoints [...] task_bp_pinned[HBP_NUM - 1] is the number of tasks having the maximum number of registers (HBP_NUM). When a breakpoint counter is created and wants an access to the pmu, we evaluate the following constraints: == Non-pinned counter == - If attached to a single cpu, check: (per_cpu(nr_bp_flexible, cpu) || (per_cpu(nr_cpu_bp_pinned, cpu) + max(per_cpu(task_bp_pinned, cpu)))) < HBP_NUM -> If there are already non-pinned counters in this cpu, it means there is already a free slot for them. Otherwise, we check that the maximum number of per task breakpoints (for this cpu) plus the number of per cpu breakpoint (for this cpu) doesn't cover every registers. - If attached to every cpus, check: (per_cpu(nr_bp_flexible, *) || (max(per_cpu(nr_cpu_bp_pinned, *)) + max(per_cpu(task_bp_pinned, *)))) < HBP_NUM -> This is roughly the same, except we check the number of per cpu bp for every cpu and we keep the max one. Same for the per tasks breakpoints. == Pinned counter == - If attached to a single cpu, check: ((per_cpu(nr_bp_flexible, cpu) > 1) + per_cpu(nr_cpu_bp_pinned, cpu) + max(per_cpu(task_bp_pinned, cpu))) < HBP_NUM -> Same checks as before. But now the nr_bp_flexible, if any, must keep one register at least (or flexible breakpoints will never be be fed). - If attached to every cpus, check: ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *)) + max(per_cpu(task_bp_pinned, *))) < HBP_NUM Changes in v2: - Counter -> event rename Changes in v5: - Fix unreleased non-pinned task-bound-only counters. We only released it in the first cpu. (Thanks to Paul Mackerras for reporting that) Changes in v6: - Currently, events scheduling are done in this order: cpu context pinned + cpu context non-pinned + task context pinned + task context non-pinned events. Then our current constraints are right theoretically but not in practice, because non-pinned counters may be scheduled before we can apply every possible pinned counters. So consider non-pinned counters as pinned for now. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
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由 Frederic Weisbecker 提交于
This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
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由 Cyrill Gorcunov 提交于
root_task_group_empty is used only with FAIR_GROUP_SCHED so if we use other scheduler options we get: kernel/sched.c:314: warning: 'root_task_group_empty' defined but not used So move CONFIG_FAIR_GROUP_SCHED up that it covers root_task_group_empty(). Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091026192414.GB5321@lenovo> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Randy Dunlap 提交于
Fix variable name in sched.c kernel-doc notation. Fixes this DocBook warning: Warning(kernel/sched.c:2008): No description found for parameter 'p' Warning(kernel/sched.c:2008): Excess function parameter 'k' description in 'kthread_bind' Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> LKML-Reference: <4AF4B1BC.8020604@oracle.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Frederic Weisbecker 提交于
While tracing using events with perf, if one enables the lockdep:lock_acquire event, it will infect every other perf trace events. Basically, you can enable whatever set of trace events through perf but if this event is part of the set, the only result we can get is a long list of lock_acquire events of rcu read lock, and only that. This is because of a recursion inside perf. 1) When a trace event is triggered, it will fill a per cpu buffer and submit it to perf. 2) Perf will commit this event but will also protect some data using rcu_read_lock 3) A recursion appears: rcu_read_lock triggers a lock_acquire event that will fill the per cpu event and then submit the buffer to perf. 4) Perf detects a recursion and ignores it 5) Perf continues its work on the previous event, but its buffer has been overwritten by the lock_acquire event, it has then been turned into a lock_acquire event of rcu read lock Such scenario also happens with lock_release with rcu_read_unlock(). We could turn the rcu_read_lock() into __rcu_read_lock() to drop the lock debugging from perf fast path, but that would make us lose the rcu debugging and that doesn't prevent from other possible kind of recursion from perf in the future. This patch adds a recursion protection based on a counter on the perf trace per cpu buffers to solve the problem. -v2: Fixed lost whitespace, added reviewed-by tag Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Reviewed-by: NMasami Hiramatsu <mhiramat@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <1257477185-7838-1-git-send-email-fweisbec@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Yong Zhang 提交于
Prarit reported: ================================= [ INFO: inconsistent lock state ] 2.6.32-rc5 #1 --------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138 {IN-HARDIRQ-W} state was registered at: [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d [<ffffffff814cdadd>] _spin_lock+0x40/0x89 [<ffffffff810c3389>] handle_level_irq+0x30/0x105 [<ffffffff81014e0e>] handle_irq+0x95/0xb7 [<ffffffff810141bd>] do_IRQ+0x6a/0xe0 [<ffffffff81012813>] ret_from_intr+0x0/0x16 irq event stamp: 195096 hardirqs last enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95 softirqs last enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30 other info that might help us debug this: 1 lock held by swapper/0: #0: (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>] run_timer_softirq+0x1a9/0x315 stack backtrace: Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1 Call Trace: <IRQ> [<ffffffff81093e94>] valid_state+0x187/0x1ae [<ffffffff81093fe4>] mark_lock+0x129/0x253 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d [<ffffffff814cdadd>] _spin_lock+0x40/0x89 [<ffffffff810c264e>] try_one_irq+0x32/0x138 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef [<ffffffff8101304c>] call_softirq+0x1c/0x30 [<ffffffff81014b65>] do_softirq+0x59/0xca [<ffffffff810686ad>] irq_exit+0x58/0xae [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20 The reason is that try_one_irq() is called from hardirq context with interrupts disabled and from softirq context (poll_all_shared_irqs()) with interrupts enabled. Disable interrupts before calling it from poll_all_shared_irqs(). Reported-and-tested-by: NPrarit Bhargava <prarit@redhat.com> Signed-off-by: NYong Zhang <yong.zhang0@gmail.com> LKML-Reference: <1257563773-4620-1-git-send-email-yong.zhang0@gmail.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 04 11月, 2009 5 次提交
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由 Masami Hiramatsu 提交于
Rename Kprobes-based event tracer to kprobes-based tracing event (kprobe-event), since it is not a tracer but an extensible tracing event interface. This also changes CONFIG_KPROBE_TRACER to CONFIG_KPROBE_EVENT and sets it y by default. Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com> Acked-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> LKML-Reference: <20091104001247.3454.14131.stgit@harusame> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Li Zefan 提交于
When a command is passed to the set_ftrace_filter, then the ftrace_regex_lock is still held going back to user space. # echo 'do_open : foo' > set_ftrace_filter (still holding ftrace_regex_lock when returning to user space!) Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AEF7F8A.3080300@cn.fujitsu.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Lai Jiangshan 提交于
We got a sudden panic when we reduced the size of the ringbuffer. We can reproduce the panic by the following steps: echo 1 > events/sched/enable cat trace_pipe > /dev/null & while ((1)) do echo 12000 > buffer_size_kb echo 512 > buffer_size_kb done (not more than 5 seconds, panic ...) Reported-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4AF01735.9060409@cn.fujitsu.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Frederic Weisbecker 提交于
A simple callback in a perf event can be used for multiple purposes. For example it is useful for triggered based events like hardware breakpoints that need a callback to dispatch a triggered breakpoint event. v2: Simplify a bit the callback attribution as suggested by Paul Mackerras Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "K.Prasad" <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mundt <lethal@linux-sh.org>
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由 Arjan van de Ven 提交于
There are reasons for kernel code to ask for, and use, performance counters. For example, in CPU freq governors this tends to be a good idea, but there are other examples possible as well of course. This patch adds the needed bits to do enable this functionality; they have been tested in an experimental cpufreq driver that I'm working on, and the changes are all that I needed to access counters properly. [fweisbec@gmail.com: added pid to perf_event_create_kernel_counter so that we can profile a particular task too TODO: Have a better error reporting, don't just return NULL in fail case.] v2: Remove the wrong comment about the fact perf_event_create_kernel_counter must be called from a kernel thread. Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Cc: "K.Prasad" <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Avi Kivity <avi@redhat.com> LKML-Reference: <20090925122556.2f8bd939@infradead.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
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- 03 11月, 2009 5 次提交
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由 Ian Campbell 提交于
nr_processes() returns the sum of the per cpu counter process_counts for all online CPUs. This counter is incremented for the current CPU on fork() and decremented for the current CPU on exit(). Since a process does not necessarily fork and exit on the same CPU the process_count for an individual CPU can be either positive or negative and effectively has no meaning in isolation. Therefore calculating the sum of process_counts over only the online CPUs omits the processes which were started or stopped on any CPU which has since been unplugged. Only the sum of process_counts across all possible CPUs has meaning. The only caller of nr_processes() is proc_root_getattr() which calculates the number of links to /proc as stat->nlink = proc_root.nlink + nr_processes(); You don't have to be all that unlucky for the nr_processes() to return a negative value leading to a negative number of links (or rather, an apparently enormous number of links). If this happens then you can get failures where things like "ls /proc" start to fail because they got an -EOVERFLOW from some stat() call. Example with some debugging inserted to show what goes on: # ps haux|wc -l nr_processes: CPU0: 90 nr_processes: CPU1: 1030 nr_processes: CPU2: -900 nr_processes: CPU3: -136 nr_processes: TOTAL: 84 proc_root_getattr. nlink 12 + nr_processes() 84 = 96 84 # echo 0 >/sys/devices/system/cpu/cpu1/online # ps haux|wc -l nr_processes: CPU0: 85 nr_processes: CPU2: -901 nr_processes: CPU3: -137 nr_processes: TOTAL: -953 proc_root_getattr. nlink 12 + nr_processes() -953 = -941 75 # stat /proc/ nr_processes: CPU0: 84 nr_processes: CPU2: -901 nr_processes: CPU3: -137 nr_processes: TOTAL: -954 proc_root_getattr. nlink 12 + nr_processes() -954 = -942 File: `/proc/' Size: 0 Blocks: 0 IO Block: 1024 directory Device: 3h/3d Inode: 1 Links: 4294966354 Access: (0555/dr-xr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2009-11-03 09:06:55.000000000 +0000 Modify: 2009-11-03 09:06:55.000000000 +0000 Change: 2009-11-03 09:06:55.000000000 +0000 I'm not 100% convinced that the per_cpu regions remain valid for offline CPUs, although my testing suggests that they do. If not then I think the correct solution would be to aggregate the process_count for a given CPU into a global base value in cpu_down(). This bug appears to pre-date the transition to git and it looks like it may even have been present in linux-2.6.0-test7-bk3 since it looks like the code Rusty patched in http://lwn.net/Articles/64773/ was already wrong. Signed-off-by: NIan Campbell <ian.campbell@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jiri Slaby 提交于
Finish a line by \n when load_image fails in the middle of loading. Signed-off-by: NJiri Slaby <jirislaby@gmail.com> Acked-by: NPavel Machek <pavel@ucw.cz> Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
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由 Jiri Slaby 提交于
There are too many retval variables in save_image(). Thus error return value from snapshot_read_next() may be ignored and only part of the snapshot (successfully) written. Remove 'error' variable, invert the condition in the do-while loop and convert the loop to use only 'ret' variable. Switch the rest of the function to consider only 'ret'. Also make sure we end printed line by \n if an error occurs. Signed-off-by: NJiri Slaby <jirislaby@gmail.com> Acked-by: NPavel Machek <pavel@ucw.cz> Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
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由 Jiri Slaby 提交于
While cruising through the swsusp code I found few blkdev reference leaks of resume_bdev. swsusp_read: remove blkdev_put altogether. Some fail paths do not do that. swsusp_check: make sure we always put a reference on fail paths software_resume: all fail paths between swsusp_check and swsusp_read omit swsusp_close. Add it in those cases. And since swsusp_read doesn't drop the reference anymore, do it here unconditionally. [rjw: Fixed a small coding style issue.] Signed-off-by: NJiri Slaby <jirislaby@gmail.com> Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
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由 Mike Galbraith 提交于
Eric Paris reported that commit f685ceac causes boot time PREEMPT_DEBUG complaints. [ 4.590699] BUG: using smp_processor_id() in preemptible [00000000] code: rmmod/1314 [ 4.593043] caller is task_hot+0x86/0xd0 Since kthread_bind() messes with scheduler internals, move the body to sched.c, and lock the runqueue. Reported-by: NEric Paris <eparis@redhat.com> Signed-off-by: NMike Galbraith <efault@gmx.de> Tested-by: NEric Paris <eparis@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1256813310.7574.3.camel@marge.simson.net> [ v2: fix !SMP build and clean up ] Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 02 11月, 2009 3 次提交
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由 Paul E. McKenney 提交于
Very long RCU read-side critical sections (50 milliseconds or so) can cause a race between force_quiescent_state() and rcu_start_gp() as follows on kernel builds with multi-level rcu_node hierarchies: 1. CPU 0 calls force_quiescent_state(), sees that there is a grace period in progress, and acquires ->fsqlock. 2. CPU 1 detects the end of the grace period, and so cpu_quiet_msk_finish() sets rsp->completed to rsp->gpnum. This operation is carried out under the root rnp->lock, but CPU 0 has not yet acquired that lock. Note that rsp->signaled is still RCU_SAVE_DYNTICK from the last grace period. 3. CPU 1 calls rcu_start_gp(), but no one wants a new grace period, so it drops the root rnp->lock and returns. 4. CPU 0 acquires the root rnp->lock and picks up rsp->completed and rsp->signaled, then drops rnp->lock. It then enters the RCU_SAVE_DYNTICK leg of the switch statement. 5. CPU 2 invokes call_rcu(), and now needs a new grace period. It calls rcu_start_gp(), which acquires the root rnp->lock, sets rsp->signaled to RCU_GP_INIT (too bad that CPU 0 is already in the RCU_SAVE_DYNTICK leg of the switch statement!) and starts initializing the rcu_node hierarchy. If there are multiple levels to the hierarchy, it will drop the root rnp->lock and initialize the lower levels of the hierarchy. 6. CPU 0 notes that rsp->completed has not changed, which permits both CPU 2 and CPU 0 to try updating it concurrently. If CPU 0's update prevails, later calls to force_quiescent_state() can count old quiescent states against the new grace period, which can in turn result in premature ending of grace periods. Not good. This patch adds an RCU_GP_IDLE state for rsp->signaled that is set initially at boot time and any time a grace period ends. This prevents CPU 0 from getting into the workings of force_quiescent_state() in step 4. Additional locking and checks prevent the concurrent update of rsp->signaled in step 6. Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1256742889199-git-send-email-> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Thomas Gleixner 提交于
Ingo triggered the following warning: WARNING: at lib/debugobjects.c:255 debug_print_object+0x42/0x50() Hardware name: System Product Name ODEBUG: init active object type: timer_list Modules linked in: Pid: 2619, comm: dmesg Tainted: G W 2.6.32-rc5-tip+ #5298 Call Trace: [<81035443>] warn_slowpath_common+0x6a/0x81 [<8120e483>] ? debug_print_object+0x42/0x50 [<81035498>] warn_slowpath_fmt+0x29/0x2c [<8120e483>] debug_print_object+0x42/0x50 [<8120ec2a>] __debug_object_init+0x279/0x2d7 [<8120ecb3>] debug_object_init+0x13/0x18 [<810409d2>] init_timer_key+0x17/0x6f [<81041526>] free_uid+0x50/0x6c [<8104ed2d>] put_cred_rcu+0x61/0x72 [<81067fac>] rcu_do_batch+0x70/0x121 debugobjects warns about an enqueued timer being initialized. If CONFIG_USER_SCHED=y the user management code uses delayed work to remove the user from the hash table and tear down the sysfs objects. free_uid is called from RCU and initializes/schedules delayed work if the usage count of the user_struct is 0. The init/schedule happens outside of the uidhash_lock protected region which allows a concurrent caller of find_user() to reference the about to be destroyed user_struct w/o preventing the work from being scheduled. If the next free_uid call happens before the work timer expired then the active timer is initialized and the work scheduled again. The race was introduced in commit 5cb350ba (sched: group scheduling, sysfs tunables) and made more prominent by commit 3959214f (sched: delayed cleanup of user_struct) Move the init/schedule_delayed_work inside of the uidhash_lock protected region to prevent the race. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NDhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: stable@kernel.org
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由 Rusty Russell 提交于
I got a boot crash when forcing cpumasks offstack on 32 bit, because find_new_ilb() returned 3 on my UP system (nohz.cpu_mask wasn't zeroed). AFAICT the others need to be zeroed too: only nohz.ilb_grp_nohz_mask is initialized before use. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911022037.21282.rusty@rustcorp.com.au> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 29 10月, 2009 9 次提交
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由 Alexey Dobriyan 提交于
Having ->procname but not ->proc_handler is valid when PROC_SYSCTL=n, people use such combination to reduce ifdefs with non-standard handlers. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14408Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Reported-by: Peter Teoh <htmldeveloper@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
cgroup_write_X64() and cgroup_write_string() ignore the return value of strstrip(). it makes small inconsistent behavior. example: ========================= # cd /mnt/cgroup/hoge # cat memory.swappiness 60 # echo "59 " > memory.swappiness # cat memory.swappiness 59 # echo " 58" > memory.swappiness bash: echo: write error: Invalid argument This patch fixes it. Cc: Li Zefan <lizf@cn.fujitsu.com> Acked-by: NPaul Menage <menage@google.com> Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Christian Borntraeger 提交于
Since commit 02b51df1 (proc connector: add event for process becoming session leader) we have the following warning: Badness at kernel/softirq.c:143 [...] Krnl PSW : 0404c00180000000 00000000001481d4 (local_bh_enable+0xb0/0xe0) [...] Call Trace: ([<000000013fe04100>] 0x13fe04100) [<000000000048a946>] sk_filter+0x9a/0xd0 [<000000000049d938>] netlink_broadcast+0x2c0/0x53c [<00000000003ba9ae>] cn_netlink_send+0x272/0x2b0 [<00000000003baef0>] proc_sid_connector+0xc4/0xd4 [<0000000000142604>] __set_special_pids+0x58/0x90 [<0000000000159938>] sys_setsid+0xb4/0xd8 [<00000000001187fe>] sysc_noemu+0x10/0x16 [<00000041616cb266>] 0x41616cb266 The warning is ---> WARN_ON_ONCE(in_irq() || irqs_disabled()); The network code must not be called with disabled interrupts but sys_setsid holds the tasklist_lock with spinlock_irq while calling the connector. After a discussion we agreed that we can move proc_sid_connector from __set_special_pids to sys_setsid. We also agreed that it is sufficient to change the check from task_session(curr) != pid into err > 0, since if we don't change the session, this means we were already the leader and return -EPERM. One last thing: There is also daemonize(), and some people might want to get a notification in that case. Since daemonize() is only needed if a user space does kernel_thread this does not look important (and there seems to be no consensus if this connector should be called in daemonize). If we really want this, we can add proc_sid_connector to daemonize() in an additional patch (Scott?) Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com> Cc: Scott James Remnant <scott@ubuntu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NEvgeniy Polyakov <zbr@ioremap.net> Acked-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Li Zefan 提交于
commit fce29d15 ("tracing/filters: Refactor subsystem filter code") broke system filter accidentally. Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4AE810BD.3070009@cn.fujitsu.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Masami Hiramatsu 提交于
Fix find_probe_event() to compare both of event-name and event-group. Without this fix, kprobe-tracer overwrites existing same event-name probe even if its group-name is different. Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> LKML-Reference: <20091027204244.30545.27516.stgit@harusame> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Rusty Russell 提交于
We create a dummy struct kernel_param on the stack for parsing each array element, but we didn't initialize the flags word. This matters for arrays of type "bool", where the flag indicates if it really is an array of bools or unsigned int (old-style). Reported-by: NTakashi Iwai <tiwai@suse.de> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
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由 Rusty Russell 提交于
kp->arg is always true: it's the contents of that pointer we care about. Reported-by: NTakashi Iwai <tiwai@suse.de> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
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由 Rusty Russell 提交于
e180a6b7 "param: fix charp parameters set via sysfs" fixed the case where charp parameters written via sysfs were freed, leaving drivers accessing random memory. Unfortunately, storing a flag in the kparam struct was a bad idea: it's rodata so setting it causes an oops on some archs. But that's not all: 1) module_param_array() on charp doesn't work reliably, since we use an uninitialized temporary struct kernel_param. 2) there's a fundamental race if a module uses this parameter and then it's changed: they will still access the old, freed, memory. The simplest fix (ie. for 2.6.32) is to never free the memory. This prevents all these problems, at cost of a memory leak. In practice, there are only 18 places where a charp is writable via sysfs, and all are root-only writable. Reported-by: NTakashi Iwai <tiwai@suse.de> Cc: Sitsofe Wheeler <sitsofe@yahoo.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
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由 Thomas Gleixner 提交于
The requeue_pi path doesn't use unqueue_me() (and the racy lock_ptr == NULL test) nor does it use the wake_list of futex_wake() which where the reason for commit 41890f2 (futex: Handle spurious wake up) See debugging discussing on LKML Message-ID: <4AD4080C.20703@us.ibm.com> The changes in this fix to the wait_requeue_pi path were considered to be a likely unecessary, but harmless safety net. But it turns out that due to the fact that for unknown $@#!*( reasons EWOULDBLOCK is defined as EAGAIN we built an endless loop in the code path which returns correctly EWOULDBLOCK. Spurious wakeups in wait_requeue_pi code path are unlikely so we do the easy solution and return EWOULDBLOCK^WEAGAIN to user space and let it deal with the spurious wakeup. Cc: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Stultz <johnstul@linux.vnet.ibm.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> LKML-Reference: <4AE23C74.1090502@us.ibm.com> Cc: stable@kernel.org Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 28 10月, 2009 2 次提交
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由 Jiri Kosina 提交于
Commit 34d76c41 introduced percpu array update_shares_data, size of which being proportional to NR_CPUS. Unfortunately this blows up ia64 for large NR_CPUS configuration, as ia64 allows only 64k for .percpu section. Fix this by allocating this array dynamically and keep only pointer to it percpu. The per-cpu handling doesn't impose significant performance penalty on potentially contented path in tg_shares_up(). ... ffffffff8104337c: 65 48 8b 14 25 20 cd mov %gs:0xcd20,%rdx ffffffff81043383: 00 00 ffffffff81043385: 48 c7 c0 00 e1 00 00 mov $0xe100,%rax ffffffff8104338c: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp) ffffffff81043393: 00 ffffffff81043394: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp) ffffffff8104339b: 00 ffffffff8104339c: 48 01 d0 add %rdx,%rax ffffffff8104339f: 49 8d 94 24 08 01 00 lea 0x108(%r12),%rdx ffffffff810433a6: 00 ffffffff810433a7: b9 ff ff ff ff mov $0xffffffff,%ecx ffffffff810433ac: 48 89 45 b0 mov %rax,-0x50(%rbp) ffffffff810433b0: bb 00 04 00 00 mov $0x400,%ebx ffffffff810433b5: 48 89 55 c0 mov %rdx,-0x40(%rbp) ... After: ... ffffffff8104337c: 65 8b 04 25 28 cd 00 mov %gs:0xcd28,%eax ffffffff81043383: 00 ffffffff81043384: 48 98 cltq ffffffff81043386: 49 8d bc 24 08 01 00 lea 0x108(%r12),%rdi ffffffff8104338d: 00 ffffffff8104338e: 48 8b 15 d3 7f 76 00 mov 0x767fd3(%rip),%rdx # ffffffff817ab368 <update_shares_data> ffffffff81043395: 48 8b 34 c5 00 ee 6d mov -0x7e921200(,%rax,8),%rsi ffffffff8104339c: 81 ffffffff8104339d: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp) ffffffff810433a4: 00 ffffffff810433a5: b9 ff ff ff ff mov $0xffffffff,%ecx ffffffff810433aa: 48 89 7d c0 mov %rdi,-0x40(%rbp) ffffffff810433ae: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp) ffffffff810433b5: 00 ffffffff810433b6: bb 00 04 00 00 mov $0x400,%ebx ffffffff810433bb: 48 01 f2 add %rsi,%rdx ffffffff810433be: 48 89 55 b0 mov %rdx,-0x50(%rbp) ... Signed-off-by: NJiri Kosina <jkosina@suse.cz> Acked-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NTejun Heo <tj@kernel.org>
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由 Anton Blanchard 提交于
Add two more software events that are common to many cpus. Alignment faults: When a load or store is not aligned properly. Emulation faults: When an instruction is emulated in software. Both cause a very significant slowdown (100x or worse), so identifying and fixing them is very important. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NPaul Mackerras <paulus@samba.org>
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- 24 10月, 2009 5 次提交
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由 Jiri Olsa 提交于
The cpu argument is not used inside the rb_time_stamp() function. Plus fix a typo. Signed-off-by: NJiri Olsa <jolsa@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233647.118547500@goodmis.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jiri Olsa 提交于
Trivial patch to fix a documentation example and to fix a comment. Signed-off-by: NJiri Olsa <jolsa@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.871719877@goodmis.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jiri Olsa 提交于
trace_seq_printf() return value is a little ambiguous. It currently returns the length of the space available in the buffer. printf usually returns the amount written. This is not adequate here, because: trace_seq_printf(s, ""); is perfectly legal, and returning 0 would indicate that it failed. We can always see the amount written by looking at the before and after values of s->len. This is not quite the same use as printf. We only care if the string was successfully written to the buffer or not. Make trace_seq_printf() return 0 if the trace oversizes the buffer's free space, 1 otherwise. Signed-off-by: NJiri Olsa <jolsa@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.631787612@goodmis.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jiri Olsa 提交于
Instead of directly updating filp->f_pos we should update the *ppos argument. The filp->f_pos gets updated within the file_pos_write() function called from sys_write(). Signed-off-by: NJiri Olsa <jolsa@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.399670810@goodmis.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
This patch restores the effectiveness of LAST_BUDDY in preventing pgsql+oltp from collapsing due to wakeup preemption. It also switches LAST_BUDDY to exclusively do what it does best, namely mitigate the effects of aggressive wakeup preemption, which improves vmark throughput markedly, and restores mysql+oltp scalability. Since buddies are about scalability, enable them beginning at the point where we begin expanding sched_latency, namely sched_nr_latency. Previously, buddies were cleared aggressively, which seriously reduced their effectiveness. Not clearing aggressively however, produces a small drop in mysql+oltp throughput immediately after peak, indicating that LAST_BUDDY is actually doing some harm. This is right at the point where X on the desktop in competition with another load wants low latency service. Ergo, do not enable until we need to scale. To mitigate latency induced by buddies, or by a task just missing wakeup preemption, check latency at tick time. Last hunk prevents buddies from stymieing BALANCE_NEWIDLE via CACHE_HOT_BUDDY. Supporting performance tests: tip = v2.6.32-rc5-1497-ga525b32 tipx = NO_GENTLE_FAIR_SLEEPERS NEXT_BUDDY granularity knobs = 31 knobs + 31 buddies tip+x = NO_GENTLE_FAIR_SLEEPERS granularity knobs = 31 knobs (Three run averages except where noted.) vmark: ------ tip 108466 messages per second tip+ 125307 messages per second tip+x 125335 messages per second tipx 117781 messages per second 2.6.31.3 122729 messages per second mysql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 9949.89 18690.20 34801.24 34460.04 32682.88 30765.97 28305.27 25059.64 19548.08 tip+ 10013.90 18526.84 34900.38 34420.14 33069.83 32083.40 30578.30 28010.71 25605.47 tipx 9698.71 18002.70 34477.56 33420.01 32634.30 31657.27 29932.67 26827.52 21487.18 2.6.31.3 8243.11 18784.20 34404.83 33148.38 31900.32 31161.90 29663.81 25995.94 18058.86 pgsql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 13686.37 26609.25 51934.28 51347.81 49479.51 45312.65 36691.91 26851.57 24145.35 tip+ (1x) 13907.85 27135.87 52951.98 52514.04 51742.52 50705.43 49947.97 48374.19 46227.94 tip+x 13906.78 27065.81 52951.19 52542.59 52176.11 51815.94 50838.90 49439.46 46891.00 tipx 13742.46 26769.81 52351.99 51891.73 51320.79 50938.98 50248.65 48908.70 46553.84 2.6.31.3 13815.35 26906.46 52683.34 52061.31 51937.10 51376.80 50474.28 49394.47 47003.25 Signed-off-by: NMike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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