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authorRoland Dreier <rolandd@cisco.com>2007-04-18 20:20:28 -0700
committerRoland Dreier <rolandd@cisco.com>2007-05-08 18:00:37 -0700
commit1bf66a30421ca772820f489d88c16d0c430d6a67 (patch)
treeb1ab223e6908d772bcad7f9bc3382c33ad5a4490 /drivers/infiniband/core/umem.c
parentf7c6a7b5d59980b076abbf2ceeb8735591290285 (diff)
downloadlinux-linaro-stable-1bf66a30421ca772820f489d88c16d0c430d6a67.tar.gz
IB: Put rlimit accounting struct in struct ib_umem
When memory pinned with ib_umem_get() is released, ib_umem_release() needs to subtract the amount of memory being unpinned from mm->locked_vm. However, ib_umem_release() may be called with mm->mmap_sem already held for writing if the memory is being released as part of an munmap() call, so it is sometimes necessary to defer this accounting into a workqueue. However, the work struct used to defer this accounting is dynamically allocated before it is queued, so there is the possibility of failing that allocation. If the allocation fails, then ib_umem_release has no choice except to bail out and leave the process with a permanently elevated locked_vm. Fix this by allocating the structure to defer accounting as part of the original struct ib_umem, so there's no possibility of failing a later allocation if creating the struct ib_umem and pinning memory succeeds. Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband/core/umem.c')
-rw-r--r--drivers/infiniband/core/umem.c41
1 files changed, 13 insertions, 28 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 48e854cf416f..f32ca5fbb26b 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -39,13 +39,6 @@
#include "uverbs.h"
-struct ib_umem_account_work {
- struct work_struct work;
- struct mm_struct *mm;
- unsigned long diff;
-};
-
-
static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{
struct ib_umem_chunk *chunk, *tmp;
@@ -192,16 +185,15 @@ out:
}
EXPORT_SYMBOL(ib_umem_get);
-static void ib_umem_account(struct work_struct *_work)
+static void ib_umem_account(struct work_struct *work)
{
- struct ib_umem_account_work *work =
- container_of(_work, struct ib_umem_account_work, work);
-
- down_write(&work->mm->mmap_sem);
- work->mm->locked_vm -= work->diff;
- up_write(&work->mm->mmap_sem);
- mmput(work->mm);
- kfree(work);
+ struct ib_umem *umem = container_of(work, struct ib_umem, work);
+
+ down_write(&umem->mm->mmap_sem);
+ umem->mm->locked_vm -= umem->diff;
+ up_write(&umem->mm->mmap_sem);
+ mmput(umem->mm);
+ kfree(umem);
}
/**
@@ -210,7 +202,6 @@ static void ib_umem_account(struct work_struct *_work)
*/
void ib_umem_release(struct ib_umem *umem)
{
- struct ib_umem_account_work *work;
struct ib_ucontext *context = umem->context;
struct mm_struct *mm;
unsigned long diff;
@@ -222,7 +213,6 @@ void ib_umem_release(struct ib_umem *umem)
return;
diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
- kfree(umem);
/*
* We may be called with the mm's mmap_sem already held. This
@@ -233,17 +223,11 @@ void ib_umem_release(struct ib_umem *umem)
* we defer the vm_locked accounting to the system workqueue.
*/
if (context->closing && !down_write_trylock(&mm->mmap_sem)) {
- work = kmalloc(sizeof *work, GFP_KERNEL);
- if (!work) {
- mmput(mm);
- return;
- }
+ INIT_WORK(&umem->work, ib_umem_account);
+ umem->mm = mm;
+ umem->diff = diff;
- INIT_WORK(&work->work, ib_umem_account);
- work->mm = mm;
- work->diff = diff;
-
- schedule_work(&work->work);
+ schedule_work(&umem->work);
return;
} else
down_write(&mm->mmap_sem);
@@ -251,6 +235,7 @@ void ib_umem_release(struct ib_umem *umem)
current->mm->locked_vm -= diff;
up_write(&mm->mmap_sem);
mmput(mm);
+ kfree(umem);
}
EXPORT_SYMBOL(ib_umem_release);