diff options
| author |   Tanner Love <tannerlove@google.com> | 2021-06-02 14:03:38 -0400 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2021-08-10 22:50:07 +0200 |
| commit | 91cc470e797828d779cd4c1efbe8519bcb358bae (patch) | |
| tree | 9f36cb2595cd78a8d9938d002800fb0bf7e9d8a6 /include/linux/interrupt.h | |
| parent | genirq/generic_chip: Use struct_size() in kzalloc() (diff) | |
| download | wireguard-linux-91cc470e797828d779cd4c1efbe8519bcb358bae.tar.xz wireguard-linux-91cc470e797828d779cd4c1efbe8519bcb358bae.zip | |
genirq: Change force_irqthreads to a static key
With CONFIG_IRQ_FORCED_THREADING=y, testing the boolean force_irqthreads
could incur a cache line miss in invoke_softirq() and other places.
Replace the test with a static key to avoid the potential cache miss.
[ tglx: Dropped the IDE part, removed the export and updated blk-mq ]
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tanner Love <tannerlove@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210602180338.3324213-1-tannerlove.kernel@gmail.com
Diffstat (limited to 'include/linux/interrupt.h')
| -rw-r--r-- | include/linux/interrupt.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2ed65b01c961..1f22a30c0963 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -13,6 +13,7 @@ #include <linux/hrtimer.h> #include <linux/kref.h> #include <linux/workqueue.h> +#include <linux/jump_label.h> #include <linux/atomic.h> #include <asm/ptrace.h> @@ -474,12 +475,13 @@ extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, #ifdef CONFIG_IRQ_FORCED_THREADING # ifdef CONFIG_PREEMPT_RT -# define force_irqthreads (true) +# define force_irqthreads() (true) # else -extern bool force_irqthreads; +DECLARE_STATIC_KEY_FALSE(force_irqthreads_key); +# define force_irqthreads() (static_branch_unlikely(&force_irqthreads_key)) # endif #else -#define force_irqthreads (0) +#define force_irqthreads() (false) #endif #ifndef local_softirq_pending |