[Stgt-devel] [Patch 0/4] bs_mmap / kreq_send threading
Tue Oct 23 23:14:01 CEST 2007
A little threading work like we have in bs_sync for bs_mmap. The mmap
can be taken care of with a small pool of worker threads this way.
After the mmap the completed commands enter back into the main tgtd
thread and would be sent to the kernel for in-kernel drivers through
kreq_send. Unfortunately kreq_send can sleep in blk_rq_map_user or
scsi_map_user_pages and hold up processing in tgtd. So kreq_send can
add the command to a list and hand it off to a small thread pool to
process sending the replies to the kernel.
I've also included a kernel patch for our tree to change the processing
of command from userspace such that it only processes one command per
write. This allows us to thread the blk_rq_map_user/scsi_map_user_pages
calls with our thread pool.
Last patch changes the way we open the backed device in the bs_mmap code
to add O_SYNC.
Robert C. Jennings <rcjenn at us.ibm.com>
IBM Linux Technology Center, Austin
+1.512.838.4964 (t/l 678.4964)
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