[PATCH v5 0/8] x86/tlb: Concurrent TLB flushes

From: Nadav Amit
Date: Tue Feb 09 2021 - 20:03:43 EST


From: Nadav Amit <namit@xxxxxxxxxx>

This is a respin of a rebased version of an old series, which I did not
follow, as I was preoccupied with personal issues (sorry).

The series improve TLB shootdown by flushing the local TLB concurrently
with remote TLBs, overlapping the IPI delivery time with the local
flush. Performance numbers can be found in the previous version [1].

The patches are essentially the same, but rebasing on the last version
required some changes. I left the reviewed-by tags - if anyone considers
it inappropriate, please let me know (and you have my apology).

[1] https://lore.kernel.org/lkml/20190823224153.15223-1-namit@xxxxxxxxxx/

v4 -> v5:
* Rebase on 5.11
* Move concurrent smp logic to smp_call_function_many_cond()
* Remove SGI-UV patch which is not needed anymore

v3 -> v4:
* Merge flush_tlb_func_local and flush_tlb_func_remote() [Peter]
* Prevent preemption on_each_cpu(). It is not needed, but it prevents
concerns. [Peter/tglx]
* Adding acked-, review-by tags

v2 -> v3:
* Open-code the remote/local-flush decision code [Andy]
* Fix hyper-v, Xen implementations [Andrew]
* Fix redundant TLB flushes.

v1 -> v2:
* Removing the patches that Thomas took [tglx]
* Adding hyper-v, Xen compile-tested implementations [Dave]
* Removing UV [Andy]
* Adding lazy optimization, removing inline keyword [Dave]
* Restructuring patch-set

RFCv2 -> v1:
* Fix comment on flush_tlb_multi [Juergen]
* Removing async invalidation optimizations [Andy]
* Adding KVM support [Paolo]

Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-hyperv@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx

Nadav Amit (8):
smp: Run functions concurrently in smp_call_function_many_cond()
x86/mm/tlb: Unify flush_tlb_func_local() and flush_tlb_func_remote()
x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()
x86/mm/tlb: Flush remote and local TLBs concurrently
x86/mm/tlb: Privatize cpu_tlbstate
x86/mm/tlb: Do not make is_lazy dirty for no reason
cpumask: Mark functions as pure
x86/mm/tlb: Remove unnecessary uses of the inline keyword

arch/x86/hyperv/mmu.c | 10 +-
arch/x86/include/asm/paravirt.h | 6 +-
arch/x86/include/asm/paravirt_types.h | 4 +-
arch/x86/include/asm/tlbflush.h | 48 +++----
arch/x86/include/asm/trace/hyperv.h | 2 +-
arch/x86/kernel/alternative.c | 2 +-
arch/x86/kernel/kvm.c | 11 +-
arch/x86/mm/init.c | 2 +-
arch/x86/mm/tlb.c | 177 +++++++++++++++-----------
arch/x86/xen/mmu_pv.c | 11 +-
include/linux/cpumask.h | 6 +-
include/trace/events/xen.h | 2 +-
kernel/smp.c | 148 +++++++++++----------
13 files changed, 242 insertions(+), 187 deletions(-)

--
2.25.1