netdev - [PATCH net-next 5/5] ionic: Re-arrange ionic_intr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 4 Dec 2023 13:09:36 -0800
From: Shannon Nelson <shannon.nelson@....com>
To: <netdev@...r.kernel.org>, <davem@...emloft.net>, <kuba@...nel.org>,
	<edumazet@...gle.com>, <pabeni@...hat.com>
CC: <f.fainelli@...il.com>, <brett.creeley@....com>, <drivers@...sando.io>,
	Shannon Nelson <shannon.nelson@....com>
Subject: [PATCH net-next 5/5] ionic: Re-arrange ionic_intr_info struct for cache perf

From: Brett Creeley <brett.creeley@....com>

dim_coal_hw is accessed in the hotpath along with other values
from the first cacheline of ionic_intr_info. So, re-arrange
the structure so the hot path variables are on the first
cacheline.

Before:

struct ionic_intr_info {
	char                       name[32];             /*     0    32 */
	unsigned int               index;                /*    32     4 */
	unsigned int               vector;               /*    36     4 */
	u64                        rearm_count;          /*    40     8 */
	unsigned int               cpu;                  /*    48     4 */

	/* XXX 4 bytes hole, try to pack */

	cpumask_t                  affinity_mask;        /*    56  1024 */
	/* --- cacheline 16 boundary (1024 bytes) was 56 bytes ago --- */
	u32                        dim_coal_hw;          /*  1080     4 */

	/* size: 1088, cachelines: 17, members: 7 */
	/* sum members: 1080, holes: 1, sum holes: 4 */
	/* padding: 4 */
};

After:

struct ionic_intr_info {
	char                       name[32];             /*     0    32 */
	u64                        rearm_count;          /*    32     8 */
	unsigned int               index;                /*    40     4 */
	unsigned int               vector;               /*    44     4 */
	unsigned int               cpu;                  /*    48     4 */
	u32                        dim_coal_hw;          /*    52     4 */
	cpumask_t                  affinity_mask;        /*    56  1024 */

	/* size: 1080, cachelines: 17, members: 7 */
	/* last cacheline: 56 bytes */
};


Signed-off-by: Brett Creeley <brett.creeley@....com>
Signed-off-by: Shannon Nelson <shannon.nelson@....com>
Reviewed-by: Florian Fainelli <florian.fainelli@...adcom.com>
---
 drivers/net/ethernet/pensando/ionic/ionic_dev.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index 19edcb42d9fd..cee4e5c3d09a 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -269,12 +269,12 @@ struct ionic_queue {
 
 struct ionic_intr_info {
 	char name[IONIC_INTR_NAME_MAX_SZ];
+	u64 rearm_count;
 	unsigned int index;
 	unsigned int vector;
-	u64 rearm_count;
 	unsigned int cpu;
-	cpumask_t affinity_mask;
 	u32 dim_coal_hw;
+	cpumask_t affinity_mask;
 };
 
 struct ionic_cq {
-- 
2.17.1