[PATCH] trace: force 8 byte alignment when --no-huge is used

[PATCH] trace: force 8 byte alignment when --no-huge is used

[David Christensen]

Current code in eal_trace_init() specifies 8 byte alignment for CTF
generation, but fallback code in __rte_trace_mem_per_thread() does
not enforce similar requirements when calling malloc(). Modify fallback
heap requests to use posix_memalign() with proper alignment.

Signed-off-by: David Christensen <drc@linux.ibm.com>
Bugzilla-ID: 1715
---
 lib/eal/common/eal_common_trace.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/eal/common/eal_common_trace.c b/lib/eal/common/eal_common_trace.c
index be1f78a68d..3dadd58e3e 100644
--- a/lib/eal/common/eal_common_trace.c
+++ b/lib/eal/common/eal_common_trace.c
@@ -363,8 +363,11 @@ __rte_trace_mem_per_thread_alloc(void)
 		goto found;
 	}

-	/* Second attempt from heap */
-	header = malloc(trace_mem_sz(trace->buff_len));
+	/* Second attempt from heap with proper alignment*/
+        size_t mem_size = trace_mem_sz(trace->buff_len);
+        void *aligned_ptr = NULL;
+        int ret = posix_memalign(&aligned_ptr, 8, mem_size);
+        header = (ret == 0) ? aligned_ptr : NULL;
 	if (header == NULL) {
 		trace_crit("trace mem malloc attempt failed");
 		header = NULL;
--
2.43.5

RE: [EXTERNAL] [PATCH] trace: force 8 byte alignment when --no-huge is used

[Jerin Jacob]

> -----Original Message-----
> From: David Christensen <drc@linux.ibm.com>
> Sent: Thursday, July 24, 2025 5:36 AM
> To: dev@dpdk.org
> Cc: David Christensen <drc@linux.ibm.com>; Jerin Jacob <jerinj@marvell.com>;
> Sunil Kumar Kori <skori@marvell.com>; Tyler Retzlaff
> <roretzla@linux.microsoft.com>
> Subject: [EXTERNAL] [PATCH] trace: force 8 byte alignment when --no-huge is
> used
> 
> Current code in eal_trace_init() specifies 8 byte alignment for CTF generation,
> but fallback code in __rte_trace_mem_per_thread() does not enforce similar
> requirements when calling malloc(). Modify fallback heap requests to use
> posix_memalign()
> Current code in eal_trace_init() specifies 8 byte alignment for CTF generation,
> but fallback code in __rte_trace_mem_per_thread() does not enforce similar
> requirements when calling malloc(). Modify fallback heap requests to use
> posix_memalign() with proper alignment.
> 
> Signed-off-by: David Christensen <drc@linux.ibm.com>


Acked-by: Jerin Jacob <jerinj@marvell.com>



> Bugzilla-ID: 1715
> ---
>  lib/eal/common/eal_common_trace.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/eal/common/eal_common_trace.c
> b/lib/eal/common/eal_common_trace.c
> index be1f78a68d..3dadd58e3e 100644
> --- a/lib/eal/common/eal_common_trace.c
> +++ b/lib/eal/common/eal_common_trace.c
> @@ -363,8 +363,11 @@ __rte_trace_mem_per_thread_alloc(void)
>  		goto found;
>  	}
> 
> -	/* Second attempt from heap */
> -	header = malloc(trace_mem_sz(trace->buff_len));
> +	/* Second attempt from heap with proper alignment*/
> +        size_t mem_size = trace_mem_sz(trace->buff_len);
> +        void *aligned_ptr = NULL;
> +        int ret = posix_memalign(&aligned_ptr, 8, mem_size);
> +        header = (ret == 0) ? aligned_ptr : NULL;
>  	if (header == NULL) {
>  		trace_crit("trace mem malloc attempt failed");
>  		header = NULL;
> --
> 2.43.5