diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2011-07-28 08:43:51 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-04-10 00:19:53 (GMT) |
| commit | 24a92055470f7d51209baa08bc015564438d0e8a (patch) | |
| tree | ba50dfbb23c0c5633e27e7f42d729634550cf3c2 /mm/highmem.c | |
| parent | 29b03268a7cca25fc60f2b5ec62c85f426f48257 (diff) | |
| download | linux-fsl-qoriq-24a92055470f7d51209baa08bc015564438d0e8a.tar.xz | |
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. ]
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 b32b70c..b1c7d43 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". @@ -47,8 +48,9 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); 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) { |