[PATCH iproute2-next v2 0/2] Add copy-on-fork to get sys command

[PATCH iproute2-next v2 0/2] Add copy-on-fork to get sys command

[Gal Pressman]

This is the userspace part for the new copy-on-fork attribute added to
the get sys netlink command.

The new attribute indicates that the kernel copies DMA pages on fork,
hence fork support through madvise and MADV_DONTFORK is not needed.

Kernel series was merged:
https://lore.kernel.org/linux-rdma/20210418121025.66849-1-galpress@amazon.com/

Changelog -
v1->v2: https://lore.kernel.org/linux-rdma/20210428114231.96944-1-galpress@amazon.com/
* Rebase kernel headers
* Print attributes on the same line
* Simplify if statement

Thanks

Gal Pressman (2):
  rdma: update uapi headers
  rdma: Add copy-on-fork to get sys command

 rdma/include/uapi/rdma/rdma_netlink.h |  3 +++
 rdma/sys.c                            | 11 ++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

-- 
2.31.1

[PATCH iproute2-next v2 1/2] rdma: update uapi headers

[Gal Pressman]

Update rdma_netlink.h file upto kernel commit
6cc9e215eb27 ("RDMA/nldev: Add copy-on-fork attribute to get sys command")

Signed-off-by: Gal Pressman <galpress@amazon.com>
---
 rdma/include/uapi/rdma/rdma_netlink.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rdma/include/uapi/rdma/rdma_netlink.h b/rdma/include/uapi/rdma/rdma_netlink.h
index e161c245bf71..37f583ee58fc 100644
--- a/rdma/include/uapi/rdma/rdma_netlink.h
+++ b/rdma/include/uapi/rdma/rdma_netlink.h
@@ -546,6 +546,9 @@ enum rdma_nldev_attr {
 
 	RDMA_NLDEV_ATTR_MIN_RANGE,		/* u32 */
 	RDMA_NLDEV_ATTR_MAX_RANGE,		/* u32 */
+
+	RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK,	/* u8 */
+
 	/*
 	 * Always the end
 	 */
-- 
2.31.1

Re: [PATCH iproute2-next v2 1/2] rdma: update uapi headers

[Leon Romanovsky]

On Thu, Apr 29, 2021 at 09:48:02AM +0300, Gal Pressman wrote:
> Update rdma_netlink.h file upto kernel commit
> 6cc9e215eb27 ("RDMA/nldev: Add copy-on-fork attribute to get sys command")
> 
> Signed-off-by: Gal Pressman <galpress@amazon.com>
> ---
>  rdma/include/uapi/rdma/rdma_netlink.h | 3 +++
>  1 file changed, 3 insertions(+)
> 

Thanks,
Acked-by: Leon Romanovsky <leonro@nvidia.com>

[PATCH iproute2-next v2 2/2] rdma: Add copy-on-fork to get sys command

[Gal Pressman]

The new attribute indicates that the kernel copies DMA pages on fork,
hence fork support through madvise and MADV_DONTFORK is not needed.

If the attribute is not reported (expected on older kernels),
copy-on-fork is disabled.

Example:
$ rdma sys
netns shared copy-on-fork on

Signed-off-by: Gal Pressman <galpress@amazon.com>
---
 rdma/sys.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/rdma/sys.c b/rdma/sys.c
index 8fb565d70598..fd785b253e20 100644
--- a/rdma/sys.c
+++ b/rdma/sys.c
@@ -20,6 +20,7 @@ static const char *netns_modes_str[] = {
 static int sys_show_parse_cb(const struct nlmsghdr *nlh, void *data)
 {
 	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX] = {};
+	bool cof = false;
 
 	mnl_attr_parse(nlh, 0, rd_attr_cb, tb);
 
@@ -35,9 +36,17 @@ static int sys_show_parse_cb(const struct nlmsghdr *nlh, void *data)
 		else
 			mode_str = "unknown";
 
-		print_color_string(PRINT_ANY, COLOR_NONE, "netns", "netns %s\n",
+		print_color_string(PRINT_ANY, COLOR_NONE, "netns", "netns %s ",
 				   mode_str);
 	}
+
+	if (tb[RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK])
+		cof = mnl_attr_get_u8(tb[RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK]);
+
+	print_color_on_off(PRINT_ANY, COLOR_NONE, "copy-on-fork",
+			   "copy-on-fork %s\n",
+			   cof);
+
 	return MNL_CB_OK;
 }
 
-- 
2.31.1

Re: [PATCH iproute2-next v2 2/2] rdma: Add copy-on-fork to get sys command

[Leon Romanovsky]

On Thu, Apr 29, 2021 at 09:48:03AM +0300, Gal Pressman wrote:
> The new attribute indicates that the kernel copies DMA pages on fork,
> hence fork support through madvise and MADV_DONTFORK is not needed.
> 
> If the attribute is not reported (expected on older kernels),
> copy-on-fork is disabled.
> 
> Example:
> $ rdma sys
> netns shared copy-on-fork on
> 
> Signed-off-by: Gal Pressman <galpress@amazon.com>
> ---
>  rdma/sys.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 

Thanks,
Acked-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH iproute2-next v2 0/2] Add copy-on-fork to get sys command

[David Ahern]

On 4/29/21 12:48 AM, Gal Pressman wrote:
> This is the userspace part for the new copy-on-fork attribute added to
> the get sys netlink command.
> 
> The new attribute indicates that the kernel copies DMA pages on fork,
> hence fork support through madvise and MADV_DONTFORK is not needed.
> 
> Kernel series was merged:
> https://lore.kernel.org/linux-rdma/20210418121025.66849-1-galpress@amazon.com/
> 
> Changelog -
> v1->v2: https://lore.kernel.org/linux-rdma/20210428114231.96944-1-galpress@amazon.com/
> * Rebase kernel headers
> * Print attributes on the same line
> * Simplify if statement
> 
> Thanks
> 
> Gal Pressman (2):
>   rdma: update uapi headers
>   rdma: Add copy-on-fork to get sys command
> 
>  rdma/include/uapi/rdma/rdma_netlink.h |  3 +++
>  rdma/sys.c                            | 11 ++++++++++-
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 

applied to iproute2-next