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[104.155.91.135]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c20e431f42esm63763666b.34.2026.08.11.07.11.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Aug 2026 07:11:06 -0700 (PDT) Date: Tue, 11 Aug 2026 15:11:02 +0100 From: Vincent Donnefort To: Steven Rostedt Cc: mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 06/18] tracing/remotes: Add dmesg tracefs file Message-ID: References: <20260804140333.797210-1-vdonnefort@google.com> <20260804140333.797210-7-vdonnefort@google.com> <20260810184216.3484cfd6@robin> <20260811094857.69dd650b@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260811094857.69dd650b@gandalf.local.home> On Tue, Aug 11, 2026 at 09:48:57AM -0400, Steven Rostedt wrote: > On Tue, 11 Aug 2026 10:09:27 +0100 > Vincent Donnefort wrote: > > > > > This is a pre-existing issue, but if an oversized event causes > > > > trace_remote_iter_print_event() to return -EOVERFLOW, will this break > > > > the loop without calling trace_remote_iter_move()? > > > > > > > > Since the event is left unconsumed in the buffer, could this lead to an > > > > uninterruptible infinite loop (hard lockup) when reading the trace pipe? > > > > > > I'll let you answer the above. > > > > > > -- Steve > > > > I don't believe this can realistically happen, trace_seq buffer is 8K and remote > > events are really small. > > They are small until they are not ;-) > > Is there anything that forces their size to be small? > > -- Steve I don't see anything preventing the declaration of a massive print function at the moment... ... and neither the registration of an event with a size bigger than a page. Is it something we should consider? I have ignored it (in both trace_remote and simple_ring_buffer) as it seems very much unlikely anyone would do that. -- Vincent