On Thu, 1 Aug 2019 at 08:59, Andrii Nakryiko [off-list ref] wrote:

On Wed, Jul 31, 2019 at 8:21 AM Björn Töpel [off-list ref] wrote:

quoted

On Tue, 30 Jul 2019 at 19:43, Kevin Laatz [off-list ref] wrote:

quoted

This patch adds a 'flags' field to the umem_config and umem_reg structs.
This will allow for more options to be added for configuring umems.

The first use for the flags field is to add a flag for unaligned chunks
mode. These flags can either be user-provided or filled with a default.

Signed-off-by: Kevin Laatz <redacted>
Signed-off-by: Ciara Loftus <redacted>

---
v2:
  - Removed the headroom check from this patch. It has moved to the
    previous patch.

v4:
  - modified chunk flag define
---

[...]

quoted

quoted

diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
index 833a6e60d065..44a03d8c34b9 100644
--- a/tools/lib/bpf/xsk.h
+++ b/tools/lib/bpf/xsk.h

@@ -170,12 +170,14 @@ LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk);
 #define XSK_UMEM__DEFAULT_FRAME_SHIFT    12 /* 4096 bytes */
 #define XSK_UMEM__DEFAULT_FRAME_SIZE     (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
 #define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
+#define XSK_UMEM__DEFAULT_FLAGS 0

 struct xsk_umem_config {
        __u32 fill_size;
        __u32 comp_size;
        __u32 frame_size;
        __u32 frame_headroom;
+       __u32 flags;

And the flags addition here, unfortunately, requires symbol versioning
of xsk_umem__create(). That'll be the first in libbpf! :-)

xsk_umem_config is passed by pointer to xsk_umem__create(), so this
doesn't break ABI, does it?

Old application, dynamically linked to new libbpf.so will crash,
right? Old application passes old version of xsk_umem_config, and new
library accesses (non-existing) flag struct member.


Björn

quoted

Björn

quoted

 };

 /* Flags for the libbpf_flags field. */
--
2.17.1

_______________________________________________
Intel-wired-lan mailing list
Intel-wired-lan@osuosl.org
https://lists.osuosl.org/mailman/listinfo/intel-wired-lan