asm-generic/mm: stub out p{4,u}d_clear_bad() if __PAGETABLE_P{4,U}D_FOLDED (f2400abc) · Commits · 戴 / test

This came up when removing __ARCH_HAS_5LEVEL_HACK for ARC as code bloat. With this patch we see the following code reduction. | bloat-o-meter2 vmlinux-D-elide-p4d_free_tlb vmlinux-E-elide-p?d_clear_bad | add/remove: 0/2 grow/shrink: 0/0 up/down: 0/-40 (-40) | function old new delta | pud_clear_bad 20 - -20 | p4d_clear_bad 20 - -20 | Total: Before=4136930, After=4136890, chg -1.000000% Link: http://lkml.kernel.org/r/20191016162400.14796-6-vgupta@synopsys.com Signed-off-by:

Vineet Gupta <vgupta@synopsys.com> Acked-by:

Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Will Deacon <will@kernel.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/pgtable.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -558,8 +558,19 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
		* Do the tests inline, but report and clear the bad entry in mm/memory.c.
		*/
		void pgd_clear_bad(pgd_t *);

		#ifndef __PAGETABLE_P4D_FOLDED
		void p4d_clear_bad(p4d_t *);
		#else
		#define p4d_clear_bad(p4d) do { } while (0)
		#endif

		#ifndef __PAGETABLE_PUD_FOLDED
		void pud_clear_bad(pud_t *);
		#else
		#define pud_clear_bad(p4d) do { } while (0)
		#endif

		void pmd_clear_bad(pmd_t *);

		static inline int pgd_none_or_clear_bad(pgd_t *pgd)

mm/pgtable-generic.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -24,18 +24,27 @@ void pgd_clear_bad(pgd_t *pgd)
		pgd_clear(pgd);
		}

		#ifndef __PAGETABLE_P4D_FOLDED
		void p4d_clear_bad(p4d_t *p4d)
		{
		p4d_ERROR(*p4d);
		p4d_clear(p4d);
		}
		#endif

		#ifndef __PAGETABLE_PUD_FOLDED
		void pud_clear_bad(pud_t *pud)
		{
		pud_ERROR(*pud);
		pud_clear(pud);
		}
		#endif

		/*
		* Note that the pmd variant below can't be stub'ed out just as for p4d/pud
		* above. pmd folding is special and typically pmd_* macros refer to upper
		* level even when folded
		*/
		void pmd_clear_bad(pmd_t *pmd)
		{
		pmd_ERROR(*pmd);

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