提交 ddd07b75 编写于 作者: P Peter Zijlstra 提交者: Thomas Gleixner

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: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NDave 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
上级 c0a759ab
......@@ -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;
/*
......
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