Hi, Here is the 2nd version of the series to improve backup instances of the persistent ring buffer. The previous version is here:
https://lore.kernel.org/all/176779714767.4193242.1978666866487010024.st...@mhiramat.tok.corp.google.com/ In this version, I updated [1/2] to use dedicated file operations for read only instance instead of checking on each write function. Also use dedicated entries files for eventfs to remove writable control files from it. So it has only 'format' and 'id' files in readonly backup instance. Since backup instances are a kind of snapshot of the persistent ring buffer, it should be readonly. And if it is readonly there is no reason to keep it after reading all data via trace_pipe because the data has been consumed. Thus, [1/2] makes backup instances readonly (not able to write any events, cleanup trace, change buffer size). Also, [2/2] removes the backup instance after consuming all data via trace_pipe. With this improvements, even if we makes a backup instance (using the same amount of memory of the persistent ring buffer), it will be removed after reading the data automatically. --- Masami Hiramatsu (Google) (2): tracing: Make the backup instance readonly tracing: Add autoremove feature to the backup instance kernel/trace/trace.c | 227 +++++++++++++++++++++++++++++++++++-------- kernel/trace/trace.h | 20 ++++ kernel/trace/trace_boot.c | 5 + kernel/trace/trace_events.c | 75 ++++++++++---- 4 files changed, 261 insertions(+), 66 deletions(-) -- Masami Hiramatsu (Google) <[email protected]>
