diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2015-07-14 14:26:34 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-02-13 00:36:21 +0100 |
| commit | 45a00c9e3d6addeaccfb94df9422ec24695f40fe (patch) | |
| tree | e47f0cdea0010d344d9618bdaf8000c415858099 | |
| parent | db291035c01afbf0c0ba8459a47a4b9a2177324a (diff) | |
| download | rt-linux-45a00c9e3d6addeaccfb94df9422ec24695f40fe.tar.gz | |
idr: Use local lock instead of preempt enable/disable
We need to protect the per cpu variable and prevent migration.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/idr.h | 4 | ||||
| -rw-r--r-- | lib/idr.c | 43 |
2 files changed, 41 insertions, 6 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index 013fd9bc4cb6c..f62be0aec911d 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -95,10 +95,14 @@ bool idr_is_empty(struct idr *idp); * Each idr_preload() should be matched with an invocation of this * function. See idr_preload() for details. */ +#ifdef CONFIG_PREEMPT_RT_FULL +void idr_preload_end(void); +#else static inline void idr_preload_end(void) { preempt_enable(); } +#endif /** * idr_find - return pointer for given id diff --git a/lib/idr.c b/lib/idr.c index 6098336df2672..9decbe9145957 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -30,6 +30,7 @@ #include <linux/idr.h> #include <linux/spinlock.h> #include <linux/percpu.h> +#include <linux/locallock.h> #define MAX_IDR_SHIFT (sizeof(int) * 8 - 1) #define MAX_IDR_BIT (1U << MAX_IDR_SHIFT) @@ -45,6 +46,37 @@ static DEFINE_PER_CPU(struct idr_layer *, idr_preload_head); static DEFINE_PER_CPU(int, idr_preload_cnt); static DEFINE_SPINLOCK(simple_ida_lock); +#ifdef CONFIG_PREEMPT_RT_FULL +static DEFINE_LOCAL_IRQ_LOCK(idr_lock); + +static inline void idr_preload_lock(void) +{ + local_lock(idr_lock); +} + +static inline void idr_preload_unlock(void) +{ + local_unlock(idr_lock); +} + +void idr_preload_end(void) +{ + idr_preload_unlock(); +} +EXPORT_SYMBOL(idr_preload_end); +#else +static inline void idr_preload_lock(void) +{ + preempt_disable(); +} + +static inline void idr_preload_unlock(void) +{ + preempt_enable(); +} +#endif + + /* the maximum ID which can be allocated given idr->layers */ static int idr_max(int layers) { @@ -115,14 +147,14 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr) * context. See idr_preload() for details. */ if (!in_interrupt()) { - preempt_disable(); + idr_preload_lock(); new = __this_cpu_read(idr_preload_head); if (new) { __this_cpu_write(idr_preload_head, new->ary[0]); __this_cpu_dec(idr_preload_cnt); new->ary[0] = NULL; } - preempt_enable(); + idr_preload_unlock(); if (new) return new; } @@ -366,7 +398,6 @@ static void idr_fill_slot(struct idr *idr, void *ptr, int id, idr_mark_full(pa, id); } - /** * idr_preload - preload for idr_alloc() * @gfp_mask: allocation mask to use for preloading @@ -401,7 +432,7 @@ void idr_preload(gfp_t gfp_mask) WARN_ON_ONCE(in_interrupt()); might_sleep_if(gfpflags_allow_blocking(gfp_mask)); - preempt_disable(); + idr_preload_lock(); /* * idr_alloc() is likely to succeed w/o full idr_layer buffer and @@ -413,9 +444,9 @@ void idr_preload(gfp_t gfp_mask) while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) { struct idr_layer *new; - preempt_enable(); + idr_preload_unlock(); new = kmem_cache_zalloc(idr_layer_cache, gfp_mask); - preempt_disable(); + idr_preload_lock(); if (!new) break; |