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From:   "Robin H. Johnson" <robbat2@gentoo.org>
To:     linux-kernel@vger.kernel.org
Cc:     rostedt@goodmis.org, mingo@redhat.com, rjohnson@digitalocean.com,
        "Robin H. Johnson" <robbat2@gentoo.org>
Subject: [PATCH 1/2] tracing: show size of requested buffer
Date:   Mon, 30 Aug 2021 21:37:22 -0700
Message-Id: <20210831043723.13481-1-robbat2@gentoo.org>
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If the perf buffer isn't large enough, provide a hint about how large it
needs to be for whatever is running.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
---
 kernel/trace/trace_event_perf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 03be4435d103..26eed4b89100 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -400,7 +400,8 @@ void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp)
 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
 
 	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-		      "perf buffer not large enough"))
+		      "perf buffer not large enough, wanted %d, have %d",
+		      size, PERF_MAX_TRACE_SIZE))
 		return NULL;
 
 	*rctxp = rctx = perf_swevent_get_recursion_context();
-- 
2.33.0