[lttng-dev] [RFC PATCH lttng-modules 10/10] callstack context: bump number of entries to 128

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Fri Mar 31 13:17:19 UTC 2017


Use a limit that fits in a 4096 bytes page on a 64-bit system. The only
reason for the prior 25 entries limitation was a bug in the header size
calculation (now fixed).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
---
 lttng-context-callstack.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lttng-context-callstack.c b/lttng-context-callstack.c
index bdc1761..fd730bb 100644
--- a/lttng-context-callstack.c
+++ b/lttng-context-callstack.c
@@ -32,7 +32,7 @@
  *
  *   size = cpus * nest * depth * sizeof(unsigned long)
  *
- * Which is about 800 bytes per CPU on 64-bit host and a depth of 25.
+ * Which is 4096 bytes per CPU on 64-bit host and a depth of 128.
  * The allocation is done at the initialization to avoid memory
  * allocation overhead while tracing, using a shallow stack.
  *
@@ -62,7 +62,7 @@
 #include "wrapper/vmalloc.h"
 #include "lttng-tracer.h"
 
-#define MAX_ENTRIES 25
+#define MAX_ENTRIES 128
 
 enum lttng_cs_ctx_modes {
 	CALLSTACK_KERNEL = 0,
-- 
2.1.4



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