On Mon, 16 Jun 2025 07:31:19 +0200 Christoph Hellwig <h...@lst.de> wrote:
> > I just did an analysis of this: > > > > > > https://lore.kernel.org/lkml/20250613104240.509ff...@batman.local.home/T/#md81abade0df19ba9062fd51ced4458161f885ac3 > > > > A TRACE_EVENT() is about 5K, and each DEFINE_EVENT() is about 1K. > > That's really quite expensive. And you only measured the tezt/data/bss Yes. This is something I've spent a bit of time over the years trying to address. With moving a bunch of code into trace_event.c with the added expense that trace events do function calls. It looks like it's still growing as the last time I checked it was just under 5K (something around 4800 bytes) and now it's over 5K, and the tracepoint code grew 4x. I'll start looking into "why" later when I have more time to deal with this. My time budget for removing unused events has pretty much dried up. > overhead and not even the dynamic memory overhead, which is probably > a lot more. Yes, and this is another area I look to make better. It was the motivation for eventfs which saved over 20 megs of memory by having trace event files dynamically created instead of being permanent. -- Steve
