Bug 7412 - mdev: implement a daemon which receives kernel uevents via a netlink socket
Summary: mdev: implement a daemon which receives kernel uevents via a netlink socket
Status: NEW
Alias: None
Product: Busybox
Classification: Unclassified
Component: Other (show other bugs)
Version: 1.22.x
Hardware: PC Linux
: P5 enhancement
Target Milestone: ---
Assignee: unassigned
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-09-10 14:46 UTC by Christoph Schulz
Modified: 2014-09-10 14:46 UTC (History)
1 user (show)

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implement a daemon which receives kernel uevents via a netlink socket (6.59 KB, patch)
2014-09-10 14:46 UTC, Christoph Schulz 		Details
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Description Christoph Schulz 2014-09-10 14:46:23 UTC 
Created attachment 5642 [details]
implement a daemon which receives kernel uevents via a netlink socket

At least since 2.6.13, the Linux kernel implements an efficient netlink socket protocol to notify user space about events (adding or removal of devices etc.), which is also used by udev. This patch adds this functionality to mdev, making it configurable at build-time by the CONFIG_FEATURE_MDEV_NETLINK setting. The main (if not _the_ advantage) is that using netlink, it is not necessary to spawn an mdev process for each event, reducing the system load at boot time considerably. Furthermode, there is no need to maintain and check the sequence file mdev.seq for serializing event processing (which did not work reliably anyway, at least not for us).

This implementation currently always serializes processing of netlink events, as if mdev.seq was available; processing netlink events in parallel is not supported by CONFIG_FEATURE_MDEV_NETLINK yet.