From 46591962cb5bfd2bfb0baf42497119c816503598 Mon Sep 17 00:00:00 2001 From: Xie XiuQi Date: Tue, 30 Jul 2013 11:06:09 +0800 Subject: generic-ipi: Kill unnecessary variable - csd_flags After commit 8969a5ede0f9e17da4b943712429aef2c9bcd82b ("generic-ipi: remove kmalloc()"), wait = 0 can be guaranteed, and all callsites of generic_exec_single() do an unconditional csd_lock() now. So csd_flags is unnecessary now. Remove it. Signed-off-by: Xie XiuQi Signed-off-by: Peter Zijlstra Cc: Oleg Nesterov Cc: Linus Torvalds Cc: Nick Piggin Cc: Jens Axboe Cc: "Paul E. McKenney" Cc: Rusty Russell Link: http://lkml.kernel.org/r/51F72DA1.7010401@huawei.com Signed-off-by: Ingo Molnar --- kernel/smp.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) (limited to 'kernel/smp.c') diff --git a/kernel/smp.c b/kernel/smp.c index fe9f773d7114..7332697cd184 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -186,25 +186,13 @@ void generic_smp_call_function_single_interrupt(void) while (!list_empty(&list)) { struct call_single_data *csd; - unsigned int csd_flags; csd = list_entry(list.next, struct call_single_data, list); list_del(&csd->list); - /* - * 'csd' can be invalid after this call if flags == 0 - * (when called through generic_exec_single()), - * so save them away before making the call: - */ - csd_flags = csd->flags; - csd->func(csd->info); - /* - * Unlocked CSDs are valid through generic_exec_single(): - */ - if (csd_flags & CSD_FLAG_LOCK) - csd_unlock(csd); + csd_unlock(csd); } } -- cgit v1.2.3 From 15e71911fcc655508e02f767a3d9b8b138051d2b Mon Sep 17 00:00:00 2001 From: Xie XiuQi Date: Mon, 29 Jul 2013 11:52:24 +0800 Subject: generic-ipi/locking: Fix misleading smp_call_function_any() description Fix locking description: after commit 8969a5ede0f9e17da4b9437 ("generic-ipi: remove kmalloc()"), wait = 0 can be guaranteed because we don't kmalloc() anymore. Signed-off-by: Xie XiuQi Cc: Sheng Yang Cc: Peter Zijlstra Cc: Jens Axboe Cc: Rusty Russell Link: http://lkml.kernel.org/r/51F5E6F8.1000801@huawei.com Signed-off-by: Ingo Molnar --- kernel/smp.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/smp.c') diff --git a/kernel/smp.c b/kernel/smp.c index fe9f773d7114..b1c9034bdfcb 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -278,8 +278,6 @@ EXPORT_SYMBOL(smp_call_function_single); * @wait: If true, wait until function has completed. * * Returns 0 on success, else a negative status code (if no cpus were online). - * Note that @wait will be implicitly turned on in case of allocation failures, - * since we fall back to on-stack allocation. * * Selection preference: * 1) current cpu if in @mask -- cgit v1.2.3 From 60c323699bb308404dcb60e8808531e02651578a Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Wed, 11 Sep 2013 14:23:22 -0700 Subject: kernel/smp.c: free related resources when failure occurs in hotplug_cfd() When failure occurs in hotplug_cfd(), need release related resources, or will cause memory leak. Signed-off-by: Chen Gang Acked-by: Wang YanQing Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/smp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/smp.c') diff --git a/kernel/smp.c b/kernel/smp.c index 449b707fc20d..3bb6ae533cdf 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -48,10 +48,13 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) cpu_to_node(cpu))) return notifier_from_errno(-ENOMEM); if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL, - cpu_to_node(cpu))) + cpu_to_node(cpu))) { + free_cpumask_var(cfd->cpumask); return notifier_from_errno(-ENOMEM); + } cfd->csd = alloc_percpu(struct call_single_data); if (!cfd->csd) { + free_cpumask_var(cfd->cpumask_ipi); free_cpumask_var(cfd->cpumask); return notifier_from_errno(-ENOMEM); } -- cgit v1.2.3 From 202da400570d991bacda4a06e878cb901e96a783 Mon Sep 17 00:00:00 2001 From: David Daney Date: Wed, 11 Sep 2013 14:23:29 -0700 Subject: kernel/smp.c: quit unconditionally enabling irqs in on_each_cpu_mask(). As in commit f21afc25f9ed ("smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu()"), we don't want to enable irqs if they are not already enabled. I don't know of any bugs currently caused by this unconditional local_irq_enable(), but I want to use this function in MIPS/OCTEON early boot (when we have early_boot_irqs_disabled). This also makes this function have similar semantics to on_each_cpu() which is good in itself. Signed-off-by: David Daney Cc: Gilad Ben-Yossef Cc: Christoph Lameter Cc: Chris Metcalf Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/smp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'kernel/smp.c') diff --git a/kernel/smp.c b/kernel/smp.c index 3bb6ae533cdf..0564571dcdf7 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -575,8 +575,10 @@ EXPORT_SYMBOL(on_each_cpu); * * If @wait is true, then returns once @func has returned. * - * You must not call this function with disabled interrupts or - * from a hardware interrupt handler or from a bottom half handler. + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. The + * exception is that it may be used during early boot while + * early_boot_irqs_disabled is set. */ void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait) @@ -585,9 +587,10 @@ void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, smp_call_function_many(mask, func, info, wait); if (cpumask_test_cpu(cpu, mask)) { - local_irq_disable(); + unsigned long flags; + local_irq_save(flags); func(info); - local_irq_enable(); + local_irq_restore(flags); } put_cpu(); } -- cgit v1.2.3