linux/arch/powerpc
Nicholas Piggin b755745147 KVM: PPC: Book3S HV: Lockless tlbie for HPT hcalls
tlbies to an LPAR do not have to be serialised since POWER4/PPC970,
after which the MMU_FTR_LOCKLESS_TLBIE feature was introduced to
avoid tlbie locking.

Since commit c17b98cf60 ("KVM: PPC: Book3S HV: Remove code for
PPC970 processors"), KVM no longer supports processors that do not
have this feature, so the tlbie locking can be removed completely.
A sanity check for the feature is put in kvmppc_mmu_hv_init.

Testing was done on a POWER9 system in HPT mode, with a -smp 32 guest
in HPT mode. 32 instances of the powerpc fork benchmark from selftests
were run with --fork, and the results measured.

Without this patch, total throughput was about 13.5K/sec, and this is
the top of the host profile:

   74.52%  [k] do_tlbies
    2.95%  [k] kvmppc_book3s_hv_page_fault
    1.80%  [k] calc_checksum
    1.80%  [k] kvmppc_vcpu_run_hv
    1.49%  [k] kvmppc_run_core

After this patch, throughput was about 51K/sec, with this profile:

   21.28%  [k] do_tlbies
    5.26%  [k] kvmppc_run_core
    4.88%  [k] kvmppc_book3s_hv_page_fault
    3.30%  [k] _raw_spin_lock_irqsave
    3.25%  [k] gup_pgd_range

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
..
boot powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
configs scsi: remove the fdomain and fdomain_cs drivers 2018-03-19 22:54:47 -04:00
crypto crypto: hash - annotate algorithms taking optional key 2018-01-12 23:03:35 +11:00
include KVM: PPC: Book3S HV: Lockless tlbie for HPT hcalls 2018-05-18 15:38:23 +10:00
kernel KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
kvm KVM: PPC: Book3S HV: Lockless tlbie for HPT hcalls 2018-05-18 15:38:23 +10:00
lib powerpc/lib: Fix off-by-one in alternate feature patching 2018-04-17 00:37:48 +10:00
math-emu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm powerpc/mm/radix: implement LPID based TLB flushes to be used by KVM 2018-05-17 11:13:29 +10:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-05 11:29:24 -08:00
oprofile powerpc: Use sizeof(*foo) rather than sizeof(struct foo) 2018-03-20 16:47:53 +11:00
perf powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
platforms rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops 2018-04-25 13:24:13 +10:00
purgatory License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysdev powerpc/xive: Fix trying to "push" an already active pool VP 2018-04-19 00:49:45 +10:00
tools License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xmon Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
Kconfig kexec_file: make use of purgatory optional 2018-04-13 17:10:27 -07:00
Kconfig.debug powerpc: Add new kconfig CONFIG_PPC_IRQ_SOFT_MASK_DEBUG 2018-01-19 22:37:03 +11:00
Makefile powerpc/64s: Add POWER9 CPU type selection 2018-04-01 22:15:32 +10:00
Makefile.postlink License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00