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Date: Mon, 4 Mar 2024 19:18:04 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Linux Trace Kernel
 <linux-trace-kernel@vger.kernel.org>, Masami Hiramatsu
 <mhiramat@kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>,
 Sachin Sant <sachinp@linux.ibm.com>
Subject: Re: [PATCH] tracing: Remove precision vsnprintf() check from print
 event
Message-ID: <20240304191804.0c48e532@gandalf.local.home>
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On Mon, 4 Mar 2024 18:55:00 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon, 4 Mar 2024 18:23:41 -0500
> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> 
> > It appears to currently be limited by
> > 
> > #define TRACE_SEQ_BUFFER_SIZE   (PAGE_SIZE * 2 - \
> >          (sizeof(struct seq_buf) + sizeof(size_t) + sizeof(int)))
> > 
> > checked within tracing_mark_write().  
> 
> Yeah, I can hard code this to 8K as it handles output of complete events,
> that can dump a lot of data, and then limit the trace_marker writes to be 4K.

Actually, the trace_marker writes is already limited by
TRACE_SEQ_BUFFER_SIZE, and by making this hard coded to 8K, it limits the
size of the trace_marker writes.

I may make the writes even smaller.

-- Steve