Kalesh Singh 45544eee96 arm64: mremap speedup - Enable HAVE_MOVE_PMD ... HAVE_MOVE_PMD enables remapping pages at the PMD level if both the source and destination addresses are PMD-aligned. HAVE_MOVE_PMD is already enabled on x86. The original patch [1] that introduced this config did not enable it on arm64 at the time because of performance issues with flushing the TLB on every PMD move. These issues have since been addressed in more recent releases with improvements to the arm64 TLB invalidation and core mmu_gather code as Will Deacon mentioned in [2]. >From the data below, it can be inferred that there is approximately 8x improvement in performance when HAVE_MOVE_PMD is enabled on arm64. --------- Test Results ---------- The following results were obtained on an arm64 device running a 5.4 kernel, by remapping a PMD-aligned, 1GB sized region to a PMD-aligned destination. The results from 10 iterations of the test are given below. All times are in nanoseconds. Control HAVE_MOVE_PMD 9220833 1247761 9002552 1219896 9254115 1094792 8725885 1227760 9308646 1043698 9001667 1101771 8793385 1159896 8774636 1143594 9553125 1025833 9374010 1078125 9100885.4 1134312.6 <-- Mean Time in nanoseconds Total mremap time for a 1GB sized PMD-aligned region drops from ~9.1 milliseconds to ~1.1 milliseconds. (~8x speedup). [1] https://lore.kernel.org/r/20181108181201.88826-3-joelaf@google.com [2] https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg140837.html Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201014005320.2233162-3-kaleshsingh@google.com Link: https://lore.kernel.org/kvmarm/20181029102840.GC13965@arm.com/ Signed-off-by: Will Deacon <will@kernel.org>		2020-10-15 11:27:28 +01:00
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alpha	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
arc	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
arm	A set of fixes for lockdep, tracing and RCU:	2020-08-30 11:43:50 -07:00
arm64	arm64: mremap speedup - Enable HAVE_MOVE_PMD	2020-10-15 11:27:28 +01:00
c6x	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
csky	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
h8300	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
hexagon	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
ia64	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
m68k	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
microblaze	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
mips	A set of fixes for lockdep, tracing and RCU:	2020-08-30 11:43:50 -07:00
nds32	A set of fixes for lockdep, tracing and RCU:	2020-08-30 11:43:50 -07:00
nios2	mm/nios2: use general page fault accounting	2020-08-12 10:58:03 -07:00
openrisc	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
parisc	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
powerpc	A set of fixes for lockdep, tracing and RCU:	2020-08-30 11:43:50 -07:00
riscv	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
s390	stacktrace: Remove reliable argument from arch_stack_walk() callback	2020-09-18 14:24:16 +01:00
sh	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
sparc	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
um	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
x86	Merge branch 'for-next/mte' into for-next/core	2020-10-02 12:16:11 +01:00
xtensa	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
.gitignore
Kconfig	A set oftimekeeping/VDSO updates:	2020-08-14 14:26:08 -07:00