Re: [PATCH v4 08/12] arm64: mm: replace TIF_LAZY_MMU with in_lazy_mmu_mode()
From: David Hildenbrand <hidden>
Date: 2025-11-03 16:03:49
Also in:
linux-arm-kernel, linux-mm, lkml, sparclinux, xen-devel
On 29.10.25 11:09, Kevin Brodsky wrote:
quoted hunk ↗ jump to hunk
The generic lazy_mmu layer now tracks whether a task is in lazy MMU mode. As a result we no longer need a TIF flag for that purpose - let's use the new in_lazy_mmu_mode() helper instead. Signed-off-by: Kevin Brodsky <redacted> --- arch/arm64/include/asm/pgtable.h | 16 +++------------- arch/arm64/include/asm/thread_info.h | 3 +-- 2 files changed, 4 insertions(+), 15 deletions(-)diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 535435248923..61ca88f94551 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h@@ -62,30 +62,21 @@ static inline void emit_pte_barriers(void) static inline void queue_pte_barriers(void) { - unsigned long flags; - if (in_interrupt()) { emit_pte_barriers(); return; } - flags = read_thread_flags(); - - if (flags & BIT(TIF_LAZY_MMU)) { - /* Avoid the atomic op if already set. */ - if (!(flags & BIT(TIF_LAZY_MMU_PENDING))) - set_thread_flag(TIF_LAZY_MMU_PENDING); - } else { + if (in_lazy_mmu_mode()) + test_and_set_thread_flag(TIF_LAZY_MMU_PENDING);
You likely don't want a test_and_set here, which would do a test_and_set_bit() -- an atomic rmw. You only want to avoid the atomic write if already set. So keep the current /* Avoid the atomic op if already set. */ if (!(flags & BIT(TIF_LAZY_MMU_PENDING))) set_thread_flag(TIF_LAZY_MMU_PENDING); -- Cheers David