diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2011-07-28 10:43:51 +0200 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-06-18 18:16:41 -0400 |
| commit | 2af1a705b6cbb47456b1f5d901dbc3ffbed4639f (patch) | |
| tree | 1d26642ddfa7e3541128169e98d3da6eee71fcd8 /mm/highmem.c | |
| parent | d887be88cc26133a4ed1f68ee04684123b983a56 (diff) | |
| download | linux-rt-2af1a705b6cbb47456b1f5d901dbc3ffbed4639f.tar.gz | |
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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[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. ]
Diffstat (limited to 'mm/highmem.c')
| -rw-r--r-- | mm/highmem.c | 6 |
1 files changed, 4 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) { |