diff options
| author |   Davidlohr Bueso <dave@stgolabs.net> | 2019-02-06 09:59:18 -0800 |
|---|---|---|
| committer |   Jason Gunthorpe <jgg@mellanox.com> | 2019-02-07 12:54:02 -0700 |
| commit | 0e15c253363e9a8824e6b9c9fc17468eb924cebd (patch) | |
| tree | e86afa16b5536b453bddf3a45f1e3b794d47a61b /drivers/infiniband/hw/hfi1 | |
| parent | drivers/IB,qib: optimize mmap_sem usage (diff) | |
| download | linux-dev-0e15c253363e9a8824e6b9c9fc17468eb924cebd.tar.xz linux-dev-0e15c253363e9a8824e6b9c9fc17468eb924cebd.zip | |
drivers/IB,hfi1: do not se mmap_sem
This driver already uses gup_fast() and thus we can just drop the mmap_sem
protection around the pinned_vm counter. Note that the window between when
hfi1_can_pin_pages() is called and the actual counter is incremented
remains the same as mmap_sem was _only_ used for when ->pinned_vm was
touched.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.det>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/hfi1')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/user_pages.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index 40a6e434190f..24b592c6522e 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -91,9 +91,7 @@ bool hfi1_can_pin_pages(struct hfi1_devdata *dd, struct mm_struct *mm, /* Convert to number of pages */ size = DIV_ROUND_UP(size, PAGE_SIZE); - down_read(&mm->mmap_sem); pinned = atomic64_read(&mm->pinned_vm); - up_read(&mm->mmap_sem); /* First, check the absolute limit against all pinned pages. */ if (pinned + npages >= ulimit && !can_lock) @@ -111,9 +109,7 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np if (ret < 0) return ret; - down_write(&mm->mmap_sem); atomic64_add(ret, &mm->pinned_vm); - up_write(&mm->mmap_sem); return ret; } @@ -130,8 +126,6 @@ void hfi1_release_user_pages(struct mm_struct *mm, struct page **p, } if (mm) { /* during close after signal, mm can be NULL */ - down_write(&mm->mmap_sem); atomic64_sub(npages, &mm->pinned_vm); - up_write(&mm->mmap_sem); } } |