v7
2026-09-01
全配置启用 per-VMA 锁并清理 · v7
让 per-VMA 锁通用化，新增等待写者的 RCU VMA 查找，并移除 binder/tcp 的 mmap_lock 回退。
原始补丁链接
子 Patch（5）
1/5
mm: Make per-VMA locks available universally
移除 ARCH_SUPPORTS_PER_VMA_LOCK 条件编译，让 per-VMA locks 在所有架构和配置（含 SMP=n）下可用；简化内核代码。
2/5
binder: Make shrinker rely solely on per-VMA lock
From: Dave Hansen dave.hansen@linux.intel.com tl;dr: lock_vma_under_rcu() is already a trylock. No need to do both it and mmap_read_trylock(). Long Version: == Background == Historically, binder
3/5
mm: Add RCU-based VMA lookup helper that waits for writers
From: Dave Hansen dave.hansen@linux.intel.com There are basically two parallel ways to look up a VMA: the traditional way, which is protected by mmap_read_lock, and the RCU-based per-VMA lock way w
4/5
binder: Remove mmap_lock fallback
From: Dave Hansen dave.hansen@linux.intel.com Previously, the per-VMA locking could fail in the face of writers which necessitate a fallback to mmap_lock. The new vma_start_read_unlocked() will wai
5/5
tcp: Remove mmap_lock fallback path
From: Dave Hansen dave.hansen@linux.intel.com Previously, the per-VMA locking could fail in the face of writers which necessitates a fallback to mmap_lock. The new vma_start_read_unlocked() will wa