diff options
| author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-02-04 16:14:30 -0500 |
|---|---|---|
| committer | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-11-04 15:52:55 -0400 |
| commit | b1ad37efcafe396ac3944853589688dd0ec3c64e (patch) | |
| tree | 49f8d3fa7080ccf85edbb75239e98a89cdd037c9 | |
| parent | 3c0cf138d7789feb3f335f6f1d24ad8fc8b3a23f (diff) | |
NVMe: Call put_nvmeq() before calling nvme_submit_sync_cmd()
We can't have preemption disabled when we call schedule(). Accept the
possibility that we'll get preempted, and it'll cost us some cacheline
bounces.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
| -rw-r--r-- | drivers/block/nvme.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index 4bfed59f362..1c3cd6cc0ad 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -842,8 +842,13 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) nvme_setup_prps(&c.common, sg, length); nvmeq = get_nvmeq(ns); - status = nvme_submit_sync_cmd(nvmeq, &c, &result); + /* Since nvme_submit_sync_cmd sleeps, we can't keep preemption + * disabled. We may be preempted at any point, and be rescheduled + * to a different CPU. That will cause cacheline bouncing, but no + * additional races since q_lock already protects against other CPUs. + */ put_nvmeq(nvmeq); + status = nvme_submit_sync_cmd(nvmeq, &c, &result); nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents); put_user(result, &uio->result); |