Messages in this thread Patch in this message |  | | Subject | Re: [RFC] sysfs: defer instantiation of default attrs | From | David Ahern <> | Date | Sat, 20 Feb 2016 09:35:25 -0700 |
| |
Hi Ed:
Thank for taking the to look into this.
On 2/20/16 3:42 AM, Edward Cree wrote: > Testing this in a VM, and with udevd disabled (being too lazy to do it > properly), created 1024 bridges. On ls'ing > /sys/class/net/bridge*/queues/*/, saw free memory drop by 64kB, > suggesting that much had been saved by deferral. It's not very much, > hopefully deferring attribute groups will do better.
That sounds consistent with what I found by cutting out attributes in netdev_register_kobject. e.g., from my patch:
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index b6c8a6629b39..f0df828a2f20 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1524,7 +1524,8 @@ int netdev_register_kobject(struct net_device *ndev) int error = 0;
device_initialize(dev); - dev->class = &net_class; + if (!netif_is_lwt(ndev)) + dev->class = &net_class; dev->platform_data = ndev; dev->groups = groups;
@@ -1535,7 +1536,8 @@ int netdev_register_kobject(struct net_device *ndev) if (*groups) groups++;
- *groups++ = &netstat_group; + if (!netif_is_lwt(ndev)) { + *groups++ = &netstat_group;
#if IS_ENABLED(CONFIG_WIRELESS_EXT) || IS_ENABLED(CONFIG_CFG80211) if (ndev->ieee80211_ptr)
The big memory savings came in when I bypassed register_queue_kobjects:
error = device_add(dev); if (error) return error; - error = register_queue_kobjects(ndev); - if (error) { - device_del(dev); - return error; + if (!netif_is_lwt(ndev)) { + error = register_queue_kobjects(ndev); + if (error) { + device_del(dev); + return error; + } } pm_runtime_set_memalloc_noio(dev, true);
Yes, this is a bit Draconian and does have impacts to tools looking for /sys files but the return is huge when you look at 1000's of netdevices (ports, vlans, bridges, bonds).
|  |