From 32aea8bf12ebc86c28091b0353d597ac144b47a1 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 28 Jul 2011 10:43:51 +0200 Subject: 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 [dvhart@linux.intel.com: build fix] Link: http://lkml.kernel.org/r/1311842631.5890.208.camel@twins --- mm/memory.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm') diff --git a/mm/memory.c b/mm/memory.c index 0d248c51a411..61744e9432cf 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3439,6 +3439,7 @@ 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 @@ -3456,6 +3457,7 @@ void pagefault_enable(void) */ barrier(); current->pagefault_disabled--; + migrate_enable(); } EXPORT_SYMBOL_GPL(pagefault_enable); #endif -- cgit v1.2.3