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Commit ddd07b75 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
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x86/mm/cpa: Unconditionally avoid WBINDV when we can 



CAT has happened, WBINDV is bad (even before CAT blowing away the
entire cache on a multi-core platform wasn't nice), try not to use it
ever.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarDave Hansen <dave.hansen@intel.com>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180919085947.933674526@infradead.org
parent c0a759ab

arch/x86/mm/pageattr.c

+2 −16
Original line number Diff line number Diff line
@@ -319,26 +319,12 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache, 
			    int in_flags, struct page **pages)

{

	unsigned int i, level;

#ifdef CONFIG_PREEMPT

	/*

	 * Avoid wbinvd() because it causes latencies on all CPUs,

	 * regardless of any CPU isolation that may be in effect.

	 *

	 * This should be extended for CAT enabled systems independent of

	 * PREEMPT because wbinvd() does not respect the CAT partitions and

	 * this is exposed to unpriviledged users through the graphics

	 * subsystem.

	 */

	unsigned long do_wbinvd = 0;

#else

	unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */

#endif



	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);



	on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);

	flush_tlb_all();



	if (!cache || do_wbinvd)

	if (!cache)

		return;



	/*