patches for DPDK stable branches
 help / color / mirror / Atom feed
From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
To: dev@dpdk.org
Cc: matan@mellanox.com, rasland@mellanox.com, thomas@monjalon.net,
	dekelp@mellanox.com, stable@dpdk.org
Subject: [dpdk-stable] [PATCH v2] common/mlx5: fix Rx/Tx queue doorbell record size
Date: Tue, 21 Jul 2020 11:11:29 +0000
Message-ID: <1595329889-31516-1-git-send-email-viacheslavo@mellanox.com> (raw)
In-Reply-To: <1595165997-12225-1-git-send-email-viacheslavo@mellanox.com>

When Rx/Tx queue was being created with DevX the allocated
doorbell record size was only uint64_t. That was definitely
less than size of CPU cacheline and it might have happened the
doorbell records attached to different queues handled by
different cores were allocated within same cacheline. It might
have caused the contention on doorbell record writing.

This patch extends the allocated memory size for doorbell
record to cacheline size.

Fixes: 21cae8580fd0 ("net/mlx5: allocate door-bells via DevX")
Cc: stable@dpdk.org

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>

---
v2: - rebase
    - clarify commit message, register is replaced with record

 drivers/common/mlx5/mlx5_common.c |  2 +-
 drivers/common/mlx5/mlx5_common.h | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/common/mlx5/mlx5_common.c b/drivers/common/mlx5/mlx5_common.c
index 79cd5ba..193e73b 100644
--- a/drivers/common/mlx5/mlx5_common.c
+++ b/drivers/common/mlx5/mlx5_common.c
@@ -187,7 +187,7 @@ static inline void mlx5_cpu_id(unsigned int level,
 	page->dbr_bitmap[i] |= (UINT64_C(1) << j);
 	page->dbr_count++;
 	*dbr_page = page;
-	return (((i * 64) + j) * sizeof(uint64_t));
+	return (i * CHAR_BIT * sizeof(uint64_t) + j) * MLX5_DBR_SIZE;
 }
 
 /**
diff --git a/drivers/common/mlx5/mlx5_common.h b/drivers/common/mlx5/mlx5_common.h
index 5b9b7bd..ef7b61b 100644
--- a/drivers/common/mlx5/mlx5_common.h
+++ b/drivers/common/mlx5/mlx5_common.h
@@ -214,10 +214,12 @@ enum mlx5_class {
 	MLX5_CLASS_VDPA = RTE_BIT64(1),
 };
 
-#define MLX5_DBR_PAGE_SIZE 4096 /* Must be >= 512. */
-#define MLX5_DBR_SIZE 8
-#define MLX5_DBR_PER_PAGE (MLX5_DBR_PAGE_SIZE / MLX5_DBR_SIZE)
-#define MLX5_DBR_BITMAP_SIZE (MLX5_DBR_PER_PAGE / 64)
+#define MLX5_DBR_SIZE RTE_CACHE_LINE_SIZE
+#define MLX5_DBR_PER_PAGE 64
+/* Must be >= CHAR_BIT * sizeof(uint64_t) */
+#define MLX5_DBR_PAGE_SIZE (MLX5_DBR_PER_PAGE * MLX5_DBR_SIZE)
+/* Page size must be >= 512. */
+#define MLX5_DBR_BITMAP_SIZE (MLX5_DBR_PER_PAGE / (CHAR_BIT * sizeof(uint64_t)))
 
 struct mlx5_devx_dbr_page {
 	/* Door-bell records, must be first member in structure. */
-- 
1.8.3.1


  reply	other threads:[~2020-07-21 11:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-19 13:39 [dpdk-stable] [PATCH] common/mlx5: fix receiving queue doorbell register size Viacheslav Ovsiienko
2020-07-21 11:11 ` Viacheslav Ovsiienko [this message]
2020-07-22  9:17   ` [dpdk-stable] [PATCH v2] common/mlx5: fix Rx/Tx queue doorbell record size Raslan Darawsheh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1595329889-31516-1-git-send-email-viacheslavo@mellanox.com \
    --to=viacheslavo@mellanox.com \
    --cc=dekelp@mellanox.com \
    --cc=dev@dpdk.org \
    --cc=matan@mellanox.com \
    --cc=rasland@mellanox.com \
    --cc=stable@dpdk.org \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

patches for DPDK stable branches

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://inbox.dpdk.org/stable \
		stable@dpdk.org
	public-inbox-index stable

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git