On Thu, Jun 12, 2025 at 05:24:05PM -0400, Steven Rostedt wrote: > > Trace events take up to 5K in memory for text and meta data. I have code that
Under what circumstances do they eat up that much memory? And is that per-class? Or per-tracepoint? > will trigger a warning when it detects unused tracepoints. The XFS file > system contains many events that are not called. Most of them used to be > called > but due to code refactoring the calls were removed but the trace events stayed > behind. > > Some events were added but never used. If they were recent, I just reported > them, but if they were older, this series simply removes them. TBH it'd be really nice if there was /something/ in the build path that would complain about disused tracepoints. I often put in tracepoints while developing a feature, then the code gets massively rewritten during review, and none of us remember to rip out the orphaned traces... > One is called only when CONFIG_COMPACT is defined, so an #ifdef was placed > around it. > > A couple are only called in #if 0 code (left as a reminder to fix it), so > those events are wrapped by a #if 0 as well (with a comment). > > Finally, one event is supposed to be a trace event class, but was created with > the TRACE_EVENT() macro and not the DECLARE_EVENT_CLASS() macro. This works > because a TRACE_EVENT() is simply a DECLARE_EVENT_CLASS() and DEFINE_EVENT() > where the class and event have the same name. But as this was a mistake, the > event created should not exist. > > Each patch is a stand alone patch. If you ack them, I can take them in my > tree, or if you want, you can take them. I may be adding the warning code to > linux-next near the end of the cycle, so it would be good to have this cleaned > up before hand. As this is removing dead code, it may be even OK to send them > to Linus as a fix. ...oh, you /do/ have a program and it's coming down the pipeline. Excellent <tents fingers>. :) --D > > Steven Rostedt (14): > xfs: tracing; Remove unused event xfs_reflink_cow_found > xfs: Remove unused trace event xfs_attr_remove_iter_return > xfs: Remove unused event xlog_iclog_want_sync > xfs: Remove unused event xfs_ioctl_clone > xfs: Remove unused xfs_reflink_compare_extents events > xfs: Remove unused trace event xfs_attr_rmtval_set > xfs: ifdef out unused xfs_attr events > xfs: Remove unused event xfs_attr_node_removename > xfs: Remove unused event xfs_alloc_near_error > xfs: Remove unused event xfs_alloc_near_nominleft > xfs: Remove unused event xfs_pagecache_inval > xfs: Remove usused xfs_end_io_direct events > xfs: Only create event xfs_file_compat_ioctl when CONFIG_COMPAT is > configure > xfs: Change xfs_xattr_class from a TRACE_EVENT() to > DECLARE_EVENT_CLASS() > > ---- > fs/xfs/scrub/trace.h | 2 +- > fs/xfs/xfs_trace.h | 72 > ++++++---------------------------------------------- > 2 files changed, 9 insertions(+), 65 deletions(-) >
