GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-22 06:41:39 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

[PATCH] x86/x86_64: deferred handling of writes to /proc/irqxx/smp_affinity

Browse source 
When handling writes to /proc/irq, current code is re-programming rte
entries directly. This is not recommended and could potentially cause
chipset's to lockup, or cause missing interrupts.

CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the
interrupt is pending. The same needs to be done for /proc/irq handling as well.
Otherwise user space irq balancers are really not doing the right thing.

- Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for
  lack of a generic name.
- added move_irq out of IRQ_BALANCE, and added this same to X86_64
- Added new proc handler for write, so we can do deferred write at irq
  handling time.
- Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead
  it now shows only active cpu masks, or exactly what was set.
- Provided a common move_irq implementation, instead of duplicating
  when using generic irq framework.

Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off.
Tested UP builds as well.

MSI testing: tbd: I have cards, need to look for a x-over cable, although I
did test an earlier version of this patch.  Will test in a couple days.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Zwane Mwaikambo <zwane@holomorphy.com>
Grudgingly-acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Coywolf Qi Hunt <coywolf@lovecn.org>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ashok Raj 2005-09-06 15:16:15 -07:00 • committed by Linus Torvalds
parent f63ed39c57
commit 54d5d42404
13 changed files with 253 additions and 134 deletions
Download patch file Download diff file Expand all files Collapse all files

123
include/linux/irq.h
View file

@ -71,16 +71,139 @@ typedef struct irq_desc {
unsigned int irq_count; /* For detecting broken interrupts */
unsigned int irqs_unhandled;
spinlock_t lock;
#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE)
unsigned int move_irq; /* Flag need to re-target intr dest*/
#endif
} ____cacheline_aligned irq_desc_t;
extern irq_desc_t irq_desc [NR_IRQS];
/* Return a pointer to the irq descriptor for IRQ. */
static inline irq_desc_t *
irq_descp (int irq)
{
return irq_desc + irq;
}
#include <asm/hw_irq.h> /* the arch dependent stuff */
extern int setup_irq(unsigned int irq, struct irqaction * new);
#ifdef CONFIG_GENERIC_HARDIRQS
extern cpumask_t irq_affinity[NR_IRQS];
#ifdef CONFIG_SMP
static inline void set_native_irq_info(int irq, cpumask_t mask)
{
irq_affinity[irq] = mask;
}
#else
static inline void set_native_irq_info(int irq, cpumask_t mask)
{
}
#endif
#ifdef CONFIG_SMP
#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE)
extern cpumask_t pending_irq_cpumask[NR_IRQS];
static inline void set_pending_irq(unsigned int irq, cpumask_t mask)
{
irq_desc_t *desc = irq_desc + irq;
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
desc->move_irq = 1;
pending_irq_cpumask[irq] = mask;
spin_unlock_irqrestore(&desc->lock, flags);
}
static inline void
move_native_irq(int irq)
{
cpumask_t tmp;
irq_desc_t *desc = irq_descp(irq);
if (likely (!desc->move_irq))
return;
desc->move_irq = 0;
if (likely(cpus_empty(pending_irq_cpumask[irq])))
return;
if (!desc->handler->set_affinity)
return;
/* note - we hold the desc->lock */
cpus_and(tmp, pending_irq_cpumask[irq], cpu_online_map);
/*
* If there was a valid mask to work with, please
* do the disable, re-program, enable sequence.
* This is *not* particularly important for level triggered
* but in a edge trigger case, we might be setting rte
* when an active trigger is comming in. This could
* cause some ioapics to mal-function.
* Being paranoid i guess!
*/
if (unlikely(!cpus_empty(tmp))) {
desc->handler->disable(irq);
desc->handler->set_affinity(irq,tmp);
desc->handler->enable(irq);
}
cpus_clear(pending_irq_cpumask[irq]);
}
#ifdef CONFIG_PCI_MSI
/*
* Wonder why these are dummies?
* For e.g the set_ioapic_affinity_vector() calls the set_ioapic_affinity_irq()
* counter part after translating the vector to irq info. We need to perform
* this operation on the real irq, when we dont use vector, i.e when
* pci_use_vector() is false.
*/
static inline void move_irq(int irq)
{
}
static inline void set_irq_info(int irq, cpumask_t mask)
{
}
#else // CONFIG_PCI_MSI
static inline void move_irq(int irq)
{
move_native_irq(irq);
}
static inline void set_irq_info(int irq, cpumask_t mask)
{
set_native_irq_info(irq, mask);
}
#endif // CONFIG_PCI_MSI
#else // CONFIG_GENERIC_PENDING_IRQ || CONFIG_IRQBALANCE
#define move_irq(x)
#define move_native_irq(x)
#define set_pending_irq(x,y)
static inline void set_irq_info(int irq, cpumask_t mask)
{
set_native_irq_info(irq, mask);
}
#endif // CONFIG_GENERIC_PENDING_IRQ
#else // CONFIG_SMP
#define move_irq(x)
#define move_native_irq(x)
#endif // CONFIG_SMP
extern int no_irq_affinity;
extern int noirqdebug_setup(char *str);