| Message ID | 20210429064803.58458-3-galpress@amazon.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | David Ahern |
| Headers | show |
| Series | Add copy-on-fork to get sys command | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
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>
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; }
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(-)