From: Johannes Cornelis Draaijer Date: Fri, 26 Dec 2025 22:02:28 +0000 (+0100) Subject: doc/dev: clarify meaning of `late_flags` in msgr2 X-Git-Tag: testing/wip-pdonnell-testing-20260108.183402~22^2~1 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=d3bc7c14b790bc95ae200981653e70b5d63acd49;p=ceph-ci.git doc/dev: clarify meaning of `late_flags` in msgr2 Signed-off-by: Johannes Cornelis Draaijer --- diff --git a/doc/dev/msgr2.rst b/doc/dev/msgr2.rst index e8542d3d7bb..6f799aecce5 100644 --- a/doc/dev/msgr2.rst +++ b/doc/dev/msgr2.rst @@ -206,10 +206,13 @@ Differences from msgr2.0-crc: empty). Rationale: If the frame has only one segment, it cannot be aborted and there are no crcs to store in the epilogue. -3. Unchecksummed late_flags is replaced with late_status which - builds in bit error detection by using a 4-bit nibble per flag +3. Unchecksummed ``late_flags`` is replaced with ``late_status``. + A completed frame is indicated by a ``late_flags`` value of + ``FRAME_LATE_STATUS_COMPLETE``, while an aborted frame is indicated + by a value of ``FRAME_LATE_STATUS_ABORTED``. This adjusted field + has better bit error detection by using a 4-bit nibble per flag and two code words that are Hamming Distance = 4 apart (and not - all zeros or ones). This comes at the expense of having only + all zeros or ones). This comes at the expense of having only one reserved flag, of course. Some example frames: