drivers/IB,core: reduce scope of mmap_sem
ib_umem_get() uses gup_longterm() and relies on the lock to stabilze the vma_list, so we cannot really get rid of mmap_sem altogether, but now that the counter is atomic, we can get of some complexity that mmap_sem brings with only pinned_vm. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>hifive-unleashed-5.1
parent
8ea1f989aa
commit
b95df5e3e4
|
@ -165,15 +165,12 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
|
||||||
|
|
||||||
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
||||||
|
|
||||||
down_write(&mm->mmap_sem);
|
new_pinned = atomic64_add_return(npages, &mm->pinned_vm);
|
||||||
new_pinned = atomic64_read(&mm->pinned_vm) + npages;
|
|
||||||
if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
|
if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
|
||||||
up_write(&mm->mmap_sem);
|
atomic64_sub(npages, &mm->pinned_vm);
|
||||||
ret = -ENOMEM;
|
ret = -ENOMEM;
|
||||||
goto out;
|
goto out;
|
||||||
}
|
}
|
||||||
atomic64_set(&mm->pinned_vm, new_pinned);
|
|
||||||
up_write(&mm->mmap_sem);
|
|
||||||
|
|
||||||
cur_base = addr & PAGE_MASK;
|
cur_base = addr & PAGE_MASK;
|
||||||
|
|
||||||
|
@ -233,9 +230,7 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
|
||||||
umem_release:
|
umem_release:
|
||||||
__ib_umem_release(context->device, umem, 0);
|
__ib_umem_release(context->device, umem, 0);
|
||||||
vma:
|
vma:
|
||||||
down_write(&mm->mmap_sem);
|
|
||||||
atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
|
atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
|
||||||
up_write(&mm->mmap_sem);
|
|
||||||
out:
|
out:
|
||||||
if (vma_list)
|
if (vma_list)
|
||||||
free_page((unsigned long) vma_list);
|
free_page((unsigned long) vma_list);
|
||||||
|
@ -258,25 +253,12 @@ static void __ib_umem_release_tail(struct ib_umem *umem)
|
||||||
kfree(umem);
|
kfree(umem);
|
||||||
}
|
}
|
||||||
|
|
||||||
static void ib_umem_release_defer(struct work_struct *work)
|
|
||||||
{
|
|
||||||
struct ib_umem *umem = container_of(work, struct ib_umem, work);
|
|
||||||
|
|
||||||
down_write(&umem->owning_mm->mmap_sem);
|
|
||||||
atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
|
|
||||||
up_write(&umem->owning_mm->mmap_sem);
|
|
||||||
|
|
||||||
__ib_umem_release_tail(umem);
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* ib_umem_release - release memory pinned with ib_umem_get
|
* ib_umem_release - release memory pinned with ib_umem_get
|
||||||
* @umem: umem struct to release
|
* @umem: umem struct to release
|
||||||
*/
|
*/
|
||||||
void ib_umem_release(struct ib_umem *umem)
|
void ib_umem_release(struct ib_umem *umem)
|
||||||
{
|
{
|
||||||
struct ib_ucontext *context = umem->context;
|
|
||||||
|
|
||||||
if (umem->is_odp) {
|
if (umem->is_odp) {
|
||||||
ib_umem_odp_release(to_ib_umem_odp(umem));
|
ib_umem_odp_release(to_ib_umem_odp(umem));
|
||||||
__ib_umem_release_tail(umem);
|
__ib_umem_release_tail(umem);
|
||||||
|
@ -285,26 +267,7 @@ void ib_umem_release(struct ib_umem *umem)
|
||||||
|
|
||||||
__ib_umem_release(umem->context->device, umem, 1);
|
__ib_umem_release(umem->context->device, umem, 1);
|
||||||
|
|
||||||
/*
|
|
||||||
* We may be called with the mm's mmap_sem already held. This
|
|
||||||
* can happen when a userspace munmap() is the call that drops
|
|
||||||
* the last reference to our file and calls our release
|
|
||||||
* method. If there are memory regions to destroy, we'll end
|
|
||||||
* up here and not be able to take the mmap_sem. In that case
|
|
||||||
* we defer the vm_locked accounting a workqueue.
|
|
||||||
*/
|
|
||||||
if (context->closing) {
|
|
||||||
if (!down_write_trylock(&umem->owning_mm->mmap_sem)) {
|
|
||||||
INIT_WORK(&umem->work, ib_umem_release_defer);
|
|
||||||
queue_work(ib_wq, &umem->work);
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
} else {
|
|
||||||
down_write(&umem->owning_mm->mmap_sem);
|
|
||||||
}
|
|
||||||
atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
|
atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
|
||||||
up_write(&umem->owning_mm->mmap_sem);
|
|
||||||
|
|
||||||
__ib_umem_release_tail(umem);
|
__ib_umem_release_tail(umem);
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL(ib_umem_release);
|
EXPORT_SYMBOL(ib_umem_release);
|
||||||
|
|
Loading…
Reference in New Issue