From cf6a3974016e7be82a85a2317cd1d739b2cfe6f1 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Sat, 3 Sep 2005 15:57:25 -0700 Subject: [PATCH] --- yaml --- r: 7023 b: refs/heads/master c: 1e40cd383ccc7c9f8b338c56ce28c326e25eb2fe h: refs/heads/master i: 7021: c528faf6e9dfc3b44fa4c772c9a66eb06ff05426 7019: 59cf0f60916623c558c02c9118daf01baaedbc0d 7015: bace2777ad56b6af529ec2877afedb3a73279f11 7007: 33b96faf7bce1b2970db6e3fe5d078381f1067ae v: v3 --- [refs] | 2 +- trunk/fs/aio.c | 4 ++++ trunk/include/asm-um/mmu_context.h | 10 +++++++++- 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/[refs] b/[refs] index eaa42413cd62..ea3e5909eec4 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: ed1b58d8b53519e10a35c6a2bb49cac35f439621 +refs/heads/master: 1e40cd383ccc7c9f8b338c56ce28c326e25eb2fe diff --git a/trunk/fs/aio.c b/trunk/fs/aio.c index 06d7d4390fe7..4f641abac3c0 100644 --- a/trunk/fs/aio.c +++ b/trunk/fs/aio.c @@ -567,6 +567,10 @@ static void use_mm(struct mm_struct *mm) atomic_inc(&mm->mm_count); tsk->mm = mm; tsk->active_mm = mm; + /* + * Note that on UML this *requires* PF_BORROWED_MM to be set, otherwise + * it won't work. Update it accordingly if you change it here + */ activate_mm(active_mm, mm); task_unlock(tsk); diff --git a/trunk/include/asm-um/mmu_context.h b/trunk/include/asm-um/mmu_context.h index 095bb627b96a..2edb4f1f789c 100644 --- a/trunk/include/asm-um/mmu_context.h +++ b/trunk/include/asm-um/mmu_context.h @@ -20,7 +20,15 @@ extern void force_flush_all(void); static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) { - if (old != new) + /* + * This is called by fs/exec.c and fs/aio.c. In the first case, for an + * exec, we don't need to do anything as we're called from userspace + * and thus going to use a new host PID. In the second, we're called + * from a kernel thread, and thus need to go doing the mmap's on the + * host. Since they're very expensive, we want to avoid that as far as + * possible. + */ + if (old != new && (current->flags & PF_BORROWED_MM)) force_flush_all(); }