From 513145ea66af95f1a5c744d7b5a4f4a97625e669 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 1 Oct 2018 11:05:21 +0100 Subject: genirq/debugfs: Reset domain debugfs_file on removal of the debugfs file When removing a debugfs file for a given irq domain, we fail to clear the corresponding field, meaning that the corresponding domain won't be created again if we need to do so. It turns out that this is exactly what irq_domain_update_bus_token does (delete old file, update domain name, recreate file). This doesn't have any impact other than making debug more difficult, but we do value ease of debugging... So clear the debugfs_file field. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20181001100522.180054-2-marc.zyngier@arm.com --- kernel/irq/irqdomain.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 5d9fc01b60a6..95a0acbdd4e6 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1741,6 +1741,7 @@ static void debugfs_add_domain_dir(struct irq_domain *d) static void debugfs_remove_domain_dir(struct irq_domain *d) { debugfs_remove(d->debugfs_file); + d->debugfs_file = NULL; } void __init irq_domain_debugfs_init(struct dentry *root) -- cgit v1.2.3 From 94967b55ebf3b603f2fe750ecedd896042585a1c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 1 Oct 2018 11:05:22 +0100 Subject: genirq/debugfs: Reinstate full OF path for domain name On a DT based system, we use the of_node full name to name the corresponding irq domain. We expect that name to be unique, so so that domains with the same base name won't clash (this happens on multi-node topologies, for example). Since a7e4cfb0a7ca ("of/fdt: only store the device node basename in full_name"), of_node_full_name() lies and only returns the basename. This breaks the above requirement, and we end-up with only a subset of the domains in /sys/kernel/debug/irq/domains. Let's reinstate the feature by using the fancy new %pOF format specifier, which happens to do the right thing. Fixes: a7e4cfb0a7ca ("of/fdt: only store the device node basename in full_name") Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20181001100522.180054-3-marc.zyngier@arm.com --- kernel/irq/irqdomain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 95a0acbdd4e6..3b30a4aeb0db 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -183,7 +183,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size, * unhappy about. Replace them with ':', which does * the trick and is not as offensive as '\'... */ - name = kstrdup(of_node_full_name(of_node), GFP_KERNEL); + name = kasprintf(GFP_KERNEL, "%pOF", of_node); if (!name) { kfree(domain); return NULL; -- cgit v1.2.3 From b8d62f33b7b225935649ab165d901fe8dd7f95e5 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 8 Oct 2018 13:17:26 +0200 Subject: genirq: Fix grammar s/an /a / Fix a grammar mistake in . [ mingo: While at it also fix another similar error in another comment as well. ] Signed-off-by: Geert Uytterhoeven Cc: Jiri Kosina Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20181008111726.26286-1-geert%2Brenesas@glider.be Signed-off-by: Ingo Molnar --- include/linux/interrupt.h | 2 +- kernel/irq/irqdomain.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index eeceac3376fc..1d6711c28271 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -45,7 +45,7 @@ * IRQF_PERCPU - Interrupt is per cpu * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is - * registered first in an shared interrupt is considered for + * registered first in a shared interrupt is considered for * performance reasons) * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished. * Used by threaded interrupts which need to keep the diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 3b30a4aeb0db..3366d11c3e02 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -867,7 +867,7 @@ void irq_dispose_mapping(unsigned int virq) EXPORT_SYMBOL_GPL(irq_dispose_mapping); /** - * irq_find_mapping() - Find a linux irq from an hw irq number. + * irq_find_mapping() - Find a linux irq from a hw irq number. * @domain: domain owning this hardware interrupt * @hwirq: hardware irq number in that domain space */ -- cgit v1.2.3 From e45506ac0af9b56b221863e9649fe122d8bb42ff Mon Sep 17 00:00:00 2001 From: Yangtao Li Date: Thu, 18 Oct 2018 10:21:33 -0400 Subject: softirq: Fix typo in __do_softirq() comments s/s/as [ mingo: Also add a missing 'the', add proper punctuation and clarify what 'swap' means here. ] Signed-off-by: Yangtao Li Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: alexander.levin@verizon.com Cc: frederic@kernel.org Cc: joel@joelfernandes.org Cc: paulmck@linux.vnet.ibm.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/20181018142133.12341-1-tiny.windzz@gmail.com Signed-off-by: Ingo Molnar --- kernel/softirq.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/softirq.c b/kernel/softirq.c index 6f584861d329..9526895fe4ac 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -257,9 +257,9 @@ asmlinkage __visible void __softirq_entry __do_softirq(void) int softirq_bit; /* - * Mask out PF_MEMALLOC s current task context is borrowed for the - * softirq. A softirq handled such as network RX might set PF_MEMALLOC - * again if the socket is related to swap + * Mask out PF_MEMALLOC as the current task context is borrowed for the + * softirq. A softirq handled, such as network RX, might set PF_MEMALLOC + * again if the socket is related to swapping. */ current->flags &= ~PF_MEMALLOC; -- cgit v1.2.3 From 746a923b863a1065ef77324e1e43f19b1a3eab5c Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 18 Oct 2018 15:15:05 +0200 Subject: genirq: Fix race on spurious interrupt detection Commit 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of threaded irqs") made detection of spurious interrupts work for threaded handlers by: a) incrementing a counter every time the thread returns IRQ_HANDLED, and b) checking whether that counter has increased every time the thread is woken. However for oneshot interrupts, the commit unmasks the interrupt before incrementing the counter. If another interrupt occurs right after unmasking but before the counter is incremented, that interrupt is incorrectly considered spurious: time | irq_thread() | irq_thread_fn() | action->thread_fn() | irq_finalize_oneshot() | unmask_threaded_irq() /* interrupt is unmasked */ | | /* interrupt fires, incorrectly deemed spurious */ | | atomic_inc(&desc->threads_handled); /* counter is incremented */ v This is observed with a hi3110 CAN controller receiving data at high volume (from a separate machine sending with "cangen -g 0 -i -x"): The controller signals a huge number of interrupts (hundreds of millions per day) and every second there are about a dozen which are deemed spurious. In theory with high CPU load and the presence of higher priority tasks, the number of incorrectly detected spurious interrupts might increase beyond the 99,900 threshold and cause disablement of the interrupt. In practice it just increments the spurious interrupt count. But that can cause people to waste time investigating it over and over. Fix it by moving the accounting before the invocation of irq_finalize_oneshot(). [ tglx: Folded change log update ] Fixes: 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of threaded irqs") Signed-off-by: Lukas Wunner Signed-off-by: Thomas Gleixner Cc: Mathias Duckeck Cc: Akshay Bhat Cc: Casey Fitzpatrick Cc: stable@vger.kernel.org # v3.16+ Link: https://lkml.kernel.org/r/1dfd8bbd16163940648045495e3e9698e63b50ad.1539867047.git.lukas@wunner.de --- kernel/irq/manage.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index fb86146037a7..9dbdccab3b6a 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -927,6 +927,9 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) local_bh_disable(); ret = action->thread_fn(action->irq, action->dev_id); + if (ret == IRQ_HANDLED) + atomic_inc(&desc->threads_handled); + irq_finalize_oneshot(desc, action); local_bh_enable(); return ret; @@ -943,6 +946,9 @@ static irqreturn_t irq_thread_fn(struct irq_desc *desc, irqreturn_t ret; ret = action->thread_fn(action->irq, action->dev_id); + if (ret == IRQ_HANDLED) + atomic_inc(&desc->threads_handled); + irq_finalize_oneshot(desc, action); return ret; } @@ -1020,8 +1026,6 @@ static int irq_thread(void *data) irq_thread_check_affinity(desc, action); action_ret = handler_fn(desc, action); - if (action_ret == IRQ_HANDLED) - atomic_inc(&desc->threads_handled); if (action_ret == IRQ_WAKE_THREAD) irq_wake_secondary(desc, action); -- cgit v1.2.3