The current algorithm for generating sub-context IDs is FILO. If the
contexts are not closed in that order, the uniqueness of the ID will be
compromised. I.e. logging the creation/deletion of context IDs with an
application that assigns and closes in a FIFO order reveals:
cache_id: assign: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 1
cache_id: assign: uctxt: 3 sub_ctxt: 2
cache_id: close: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 2 <<<
The sub_ctxt ID 2 is reused incorrectly.
Update the sub-context ID assign algorithm to use a bitmask of in_use
contexts. The new algorithm will allow the contexts to be closed in any
order, and will only re-use unused contexts.
Size subctxt and subctxt_cnt to match the user API size.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Since almost all functions that use the hfi1_filedata get the pointer
from the file pointer, simplify by only passing the hfi1_filedata pointer.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
To improve the readability of function prototypes, give the parameters
names.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Use the new cache evict operation in the SDMA code. This allows the cache
to properly coordinate evicts and removes, preventing any race. With this
change, the separate list, lock, and race flag are not needed.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The objects which use cache handling should reference their own handler
object not the internal data structure it uses to track the nodes.
Have the "users" of the mmu notifier code pass opaque objects which can
then be properly used in the mmu callbacks depending on the owners needs.
This patch has the additional benefit that operations no longer require a
look up in a list to find the handlers.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The hfi1 driver registers a mmu_notifier callback when /dev/hfi1_* is
opened, and unregisters it when the device is closed. The driver
incorrectly assumes that the close will always happen from the same
context as the open. In particular, closes due to SIGKILL or OOM killer
activity may happen from a different context. In these cases, the wrong
mm is passed to mmu_notifier_unregister(), which causes improper reference
counting for the victim mm, and eventual memory corruption.
Preserve the mm for all open file descriptors and use this mm rather than
current->mm for memory operations for the lifetime of that fd. Note: this
patch leaves 1 use of current->mm in place. This use is removed in a
follow on patch because other functional changes were required prior to
that use being removed.
If registration fails, there is no reason to keep the handler object
around. Free the handler object rather than add it to the list to
prevent any mmu_notifier operations, including unregister, when
registration fails.
Suggested-by: Jim Foraker <foraker1@llnl.gov>
Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The user SDMA in-use claim bit is in the structure that gets zeroed out
once the claim is made. Move the request in-use flag into its own bit
array and use that for atomic claims. This cleans up the claim code and
removes any race possibility.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The TODO list for the hfi1 driver was completed during 4.6. In addition
other objections raised (which are far beyond what was in the TODO list)
have been addressed as well. It is now time to remove the driver from
staging and into the drivers/infiniband sub-tree.
Reviewed-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Michael J. Ruhl