s390: disable pfmf for clear page instruction (617e164c) · Commits · 戴 / test

Wit the introduction of large pages Linux also used pfmf for page clearing. The current implementation is not ideal, though: - currently we set usage intent=0, but cleared pages are often used directly after the clearing - z/VM does not yet provide EDAT - KVM does have to intercept PFMF even for resident pages Lets just the mvcl loop in all cases until we have a well defined pattern were pfmf is besser. Signed-off-by:

Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/page.h

+8 −12

Original line number	Diff line number	Diff line
		@@ -32,7 +32,7 @@

		void storage_key_init_range(unsigned long start, unsigned long end);

		static unsigned long pfmf(unsigned long function, unsigned long address)
		static inline unsigned long pfmf(unsigned long function, unsigned long address)
		{
		asm volatile(
		" .insn rre,0xb9af0000,%[function],%[address]"
		@@ -44,9 +44,6 @@ static unsigned long pfmf(unsigned long function, unsigned long address)

		static inline void clear_page(void *page)
		{
		if (MACHINE_HAS_PFMF) {
		pfmf(0x10000, (unsigned long)page);
		} else {
		register unsigned long reg1 asm ("1") = 0;
		register void *reg2 asm ("2") = page;
		register unsigned long reg3 asm ("3") = 4096;
		@@ -55,7 +52,6 @@ static inline void clear_page(void *page)
		: "+d" (reg2), "+d" (reg3) : "d" (reg1)
		: "memory", "cc");
		}
		}

		static inline void copy_page(void to, void from)
		{

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