[ovs-dev] [PATCHv2] netdev-afxdp: Detect numa node id.

[William Tu]

On Mon, Sep 30, 2019 at 12:40:59PM +0200, Eelco Chaudron wrote:
> 
> 
> On 27 Sep 2019, at 19:26, William Tu wrote:
> 
> >The patch detects the numa node id from the name of the netdev,
> >by reading the '/sys/class/net/<devname>/device/numa_node'.
> >If not available, ex: virtual device, or any error happens,
> >return numa id 0.
> >
> >Signed-off-by: William Tu <u9012063 at gmail.com>
> 
> Will you update the “Limitations/Known Issues” section as part of the
> libnuma and numa_alloc_onnode() patch?

Thanks!
I will fix it in next version.

> 
> >---
> >v2:
> >  Address feedback from Eelco
> >    fix memory leak of xaspintf
> >    log using INFO instead of WARN
> >---
> > lib/netdev-afxdp.c | 41 ++++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 36 insertions(+), 5 deletions(-)
> >
> >diff --git a/lib/netdev-afxdp.c b/lib/netdev-afxdp.c
> >index 6e01803272aa..6ff1473461a6 100644
> >--- a/lib/netdev-afxdp.c
> >+++ b/lib/netdev-afxdp.c
> >@@ -552,11 +552,42 @@ out:
> > int
> > netdev_afxdp_get_numa_id(const struct netdev *netdev)
> > {
> >-    /* FIXME: Get netdev's PCIe device ID, then find
> >-     * its NUMA node id.
> >-     */
> >-    VLOG_INFO("FIXME: Device %s always use numa id 0.",
> >-              netdev_get_name(netdev));
> >+    const char *numa_node_path;
> >+    long int node_id;
> >+    char buffer[4];
> >+    FILE *stream;
> >+    int n;
> >+
> >+    numa_node_path = xasprintf("/sys/class/net/%s/device/numa_node",
> >+                               netdev_get_name(netdev));
> >+    stream = fopen(numa_node_path, "r");
> >+    if (!stream) {
> >+        /* Virtual device does not have this info. */
> >+        VLOG_INFO_RL(&rl, "Open %s failed: %s, use numa_id 0",
> >+                     numa_node_path, ovs_strerror(errno));
> >+        free(numa_node_path);
> >+        return 0;
> >+    }
> >+
> >+    n = fread(buffer, 1, sizeof buffer, stream);
> >+    if (!n) {
> >+        goto error;
> >+    }
> >+
> >+    node_id = strtol(buffer, NULL, 10);
> >+    if (node_id < 0 || node_id > 2) {
> >+        goto error;
> >+    }
> 
> Any reason why you limit this to 2? Guess it depends on the kernel’s
> CONFIG_NODES_SHIFT value. You might be able to use the libnuma API
> numa_max_possible_node().
> 

I thought most of the systems have max 2 numa...
I will fix it, thank you.

Regards,
William
> >+
> >+    fclose(stream);
> >+    free(numa_node_path);
> >+    return (int)node_id;
> 
> Guess you need a space after (int) node_id.
> 
> >+
> >+error:
> >+    VLOG_WARN_RL(&rl, "Error detecting numa node of %s, use numa_id 0",
> >+                 numa_node_path);
> >+    free(numa_node_path);
> >+    fclose(stream);
> >     return 0;
> > }
> >
> >-- 
> >2.7.4