Revision 9fcd67d1772c43d2f23e8fca56acc7219e991676 authored by David Marchand on 24 February 2017, 14:38:26 UTC, committed by Doug Ledford on 25 March 2017, 02:07:27 UTC
According to C9-147, MSN should only be incremented when the last packet of
a multi packet request has been received.
"Logically, the requester associates a sequential Send Sequence Number
(SSN) with each WQE posted to the send queue. The SSN bears a one-
to-one relationship to the MSN returned by the responder in each re-
sponse packet. Therefore, when the requester receives a response, it in-
terprets the MSN as representing the SSN of the most recent request
completed by the responder to determine which send WQE(s) can be
completed."
Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: David Marchand <david.marchand@6wind.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
1 parent 812755d
swp_emulation
Software emulation of deprecated SWP instruction (CONFIG_SWP_EMULATE)
---------------------------------------------------------------------
ARMv6 architecture deprecates use of the SWP/SWPB instructions, and recommeds
moving to the load-locked/store-conditional instructions LDREX and STREX.
ARMv7 multiprocessing extensions introduce the ability to disable these
instructions, triggering an undefined instruction exception when executed.
Trapped instructions are emulated using an LDREX/STREX or LDREXB/STREXB
sequence. If a memory access fault (an abort) occurs, a segmentation fault is
signalled to the triggering process.
/proc/cpu/swp_emulation holds some statistics/information, including the PID of
the last process to trigger the emulation to be invocated. For example:
---
Emulated SWP: 12
Emulated SWPB: 0
Aborted SWP{B}: 1
Last process: 314
---
NOTE: when accessing uncached shared regions, LDREX/STREX rely on an external
transaction monitoring block called a global monitor to maintain update
atomicity. If your system does not implement a global monitor, this option can
cause programs that perform SWP operations to uncached memory to deadlock, as
the STREX operation will always fail.
Computing file changes ...
