From 0d6e24d430ef23280d8dea0ba1faeefc66c26a57 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 3 Feb 2020 17:37:11 -0800 Subject: asm-generic/tlb: provide MMU_GATHER_TABLE_FREE As described in the comment, the correct order for freeing pages is: 1) unhook page 2) TLB invalidate page 3) free page This order equally applies to page directories. Currently there are two correct options: - use tlb_remove_page(), when all page directores are full pages and there are no futher contraints placed by things like software walkers (HAVE_FAST_GUP). - use MMU_GATHER_RCU_TABLE_FREE and tlb_remove_table() when the architecture does not do IPI based TLB invalidate and has HAVE_FAST_GUP (or software TLB fill). This however leaves architectures that don't have page based directories but don't need RCU in a bind. For those, provide MMU_GATHER_TABLE_FREE, which provides the independent batching for directories without the additional RCU freeing. Link: http://lkml.kernel.org/r/20200116064531.483522-10-aneesh.kumar@linux.ibm.com Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Aneesh Kumar K.V Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/Kconfig') diff --git a/arch/Kconfig b/arch/Kconfig index c35668fbf4d4..98de654b79b3 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -393,8 +393,12 @@ config HAVE_ARCH_JUMP_LABEL config HAVE_ARCH_JUMP_LABEL_RELATIVE bool +config MMU_GATHER_TABLE_FREE + bool + config MMU_GATHER_RCU_TABLE_FREE bool + select MMU_GATHER_TABLE_FREE config MMU_GATHER_PAGE_SIZE bool @@ -404,6 +408,7 @@ config MMU_GATHER_NO_RANGE config MMU_GATHER_NO_GATHER bool + depends on MMU_GATHER_TABLE_FREE config ARCH_HAVE_NMI_SAFE_CMPXCHG bool -- cgit v1.2.3