On Wed, Aug 18, 2021 at 08:07:28PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > Because there are a lot of tracepoints that express numeric data with > an associated unit and tag, document what they are to help everyone else > keep these thigns straight. > > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> Thanks for adding this quickly. :) > --- > fs/xfs/scrub/trace.h | 4 ++++ > fs/xfs/xfs_trace.h | 24 ++++++++++++++++++++++++ > 2 files changed, 28 insertions(+) > > diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h > index e9b81b7645c1..20f34548bfe5 100644 > --- a/fs/xfs/scrub/trace.h > +++ b/fs/xfs/scrub/trace.h > @@ -2,6 +2,10 @@ > /* > * Copyright (C) 2017 Oracle. All Rights Reserved. > * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > + * > + * NOTE: none of these tracepoints shall be considered a stable kernel ABI > + * as they can change at any time. See xfs_trace.h for documentation of > + * specific units found in tracepoint output. > */ > #undef TRACE_SYSTEM > #define TRACE_SYSTEM xfs_scrub > diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h > index a72cd56afc8c..c46dd4fea3e3 100644 > --- a/fs/xfs/xfs_trace.h > +++ b/fs/xfs/xfs_trace.h > @@ -2,6 +2,30 @@ > /* > * Copyright (c) 2009, Christoph Hellwig > * All Rights Reserved. > + * > + * NOTE: none of these tracepoints shall be considered a stable kernel ABI > + * as they can change at any time. > + * > + * Current conventions for printing numbers measuring specific units: > + * > + * ino: filesystem inode number > + * agino: per-AG inode number > + * agno: allocation group number > + * agbno: per-AG block number in fs blocks > + * owner: reverse-mapping owner, usually inodes > + * daddr: physical block number in 512b blocks > + * startblock: physical block number for file mappings. This is either a > + * segmented fsblock for data device mappings, or a rfsblock > + * for realtime device mappings > + * fileoff: file offset, in fs blocks > + * pos: file offset, in bytes > + * forkoff: inode fork offset, in bytes > + * icount: number of inode records ireccount? > + * disize: ondisk file size, in bytes > + * isize: incore file size, in bytes > + * fsbcount: number of blocks in an extent, in fs blocks > + * bbcount: number of blocks in a physical extent, in 512b blocks > + * bytecount: number of bytes > */ > #undef TRACE_SYSTEM > #define TRACE_SYSTEM xfs Only thing I'd add to this comment is that hexadecimal is the preferred output format for all these types. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
