diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2011-07-28 10:43:51 +0200 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-05-08 22:33:09 +0200 |
| commit | 24b7801df27130075c0c3cd69dfb6a53648d26f7 (patch) | |
| tree | cf3bfc6b21e7a67a31b6ce8b37f393016d329332 /mm | |
| parent | 894a3968c662eec9c48289e531adf6f44ddc25cb (diff) | |
mm, rt: kmap_atomic scheduling
In fact, with migrate_disable() existing one could play games with
kmap_atomic. You could save/restore the kmap_atomic slots on context
switch (if there are any in use of course), this should be esp easy now
that we have a kmap_atomic stack.
Something like the below.. it wants replacing all the preempt_disable()
stuff with pagefault_disable() && migrate_disable() of course, but then
you can flip kmaps around like below.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
[dvhart@linux.intel.com: build fix]
Link: http://lkml.kernel.org/r/1311842631.5890.208.camel@twins
[tglx@linutronix.de: Get rid of the per cpu variable and store the idx
and the pte content right away in the task struct.
Shortens the context switch code. ]
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/highmem.c | 6 | ||||
| -rw-r--r-- | mm/memory.c | 2 |
2 files changed, 6 insertions, 2 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index 123bcd3ed4f2..16e8cf26d38a 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -29,10 +29,11 @@ #include <linux/kgdb.h> #include <asm/tlbflush.h> - +#ifndef CONFIG_PREEMPT_RT_FULL #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) DEFINE_PER_CPU(int, __kmap_atomic_idx); #endif +#endif /* * Virtual_count is not a pure "count". @@ -107,8 +108,9 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color) unsigned long totalhigh_pages __read_mostly; EXPORT_SYMBOL(totalhigh_pages); - +#ifndef CONFIG_PREEMPT_RT_FULL EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx); +#endif unsigned int nr_free_highpages (void) { diff --git a/mm/memory.c b/mm/memory.c index e38f53b792d9..8b6028fc342e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3247,6 +3247,7 @@ unlock: #ifdef CONFIG_PREEMPT_RT_FULL void pagefault_disable(void) { + migrate_disable(); current->pagefault_disabled++; /* * make sure to have issued the store before a pagefault @@ -3264,6 +3265,7 @@ void pagefault_enable(void) */ barrier(); current->pagefault_disabled--; + migrate_enable(); } EXPORT_SYMBOL(pagefault_enable); #endif |