Re: [PATCH v4 02/12] x86/xen: simplify flush_lazy_mmu()
From: Ryan Roberts <ryan.roberts@arm.com>
Date: 2025-11-07 12:31:49
Also in:
linux-mm, linuxppc-dev, lkml, sparclinux, xen-devel
On 29/10/2025 10:08, Kevin Brodsky wrote:
arch_flush_lazy_mmu_mode() is called when outstanding batched pgtable operations must be completed immediately. There should however be no need to leave and re-enter lazy MMU completely. The only part of that sequence that we really need is xen_mc_flush(); call it directly. Signed-off-by: Kevin Brodsky <redacted>
This looks functionally equivalent to me, so: Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> But I don't think this tidy up is strictly necessary for your series to work? (perhaps I'll change my mind on that as I go through it).
quoted hunk ↗ jump to hunk
--- arch/x86/xen/mmu_pv.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 2a4a8deaf612..7a35c3393df4 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c@@ -2139,10 +2139,8 @@ static void xen_flush_lazy_mmu(void) { preempt_disable(); - if (xen_get_lazy_mode() == XEN_LAZY_MMU) { - arch_leave_lazy_mmu_mode(); - arch_enter_lazy_mmu_mode(); - } + if (xen_get_lazy_mode() == XEN_LAZY_MMU) + xen_mc_flush(); preempt_enable(); }