Re: [PATCH 4/7] x86/xen: support nested lazy_mmu sections (again)
From: Alexander Gordeev <agordeev@linux.ibm.com>
Date: 2025-09-05 15:49:23
Also in:
linux-arm-kernel, linux-mm, lkml, sparclinux, xen-devel
On Thu, Sep 04, 2025 at 01:57:33PM +0100, Kevin Brodsky wrote: ...
quoted hunk ↗ jump to hunk
-static void xen_enter_lazy_mmu(void) +static lazy_mmu_state_t xen_enter_lazy_mmu(void) { + if (this_cpu_read(xen_lazy_mode) == XEN_LAZY_MMU) + return LAZY_MMU_NESTED; + enter_lazy(XEN_LAZY_MMU); + return LAZY_MMU_DEFAULT; } static void xen_flush_lazy_mmu(void)@@ -2167,11 +2171,12 @@ static void __init xen_post_allocator_init(void) pv_ops.mmu.write_cr3 = &xen_write_cr3; } -static void xen_leave_lazy_mmu(void) +static void xen_leave_lazy_mmu(lazy_mmu_state_t state) { preempt_disable(); xen_mc_flush(); - leave_lazy(XEN_LAZY_MMU); + if (state != LAZY_MMU_NESTED) + leave_lazy(XEN_LAZY_MMU);
Based on xen_enter_lazy_mmu(), whether this condition needs to be executed with the preemption disabled? Or may be this_cpu_read(xen_lazy_mode) + enter_lazy(XEN_LAZY_MMU) should be executed with the preemption disabled?
preempt_enable(); }
Thanks!