On 12/03/2015 16:19, Natanael Copa wrote:
netlink listener code that needs to be in memory all the time: http://git.alpinelinux.org/cgit/ncopa/nldev/tree/nldev.c
A few comments: - disableoom(): it's a generic operation for any daemon you don't want to have killed, so you can factorize it: you can remove it from the always-in-memory code, and run nldev under a program such as perp's runchoom. http://b0llix.net/perp/site.cgi?page=runchoom.8 - spawn_handler(): would benefit from being implemented via posix_spawn(), to accommodate noMMU. On the other hand, you'd need two elements in the posix_spawn_file_actions_t, so depending on the implementation, that could pull in malloc(). It's a trade-off. - sighandler()/initsignals(): trapping SIGKILL is a waste of code. - init_netlink_socket(): listfd needs to be close-on-exec. - in sighandler() and at the end of main(): shutting down a socket before closing it is a waste of code when you know there are no copies of the socket. Shutting it down or closing it right before exit()ing is also a waste of code. :) - It may be worth it to write functions similar to die(), edie() and dbg() that don't use stdio, and call _exit() instead of exit(). If you manage to scrap stdio, you gain 2 pages of text (with the musl implementation). - I understand that Alpine is runit-based. Save even more space by scrapping all the dofork nonsense and saying that nldev should be supervised. - line 213: ew. Please don't do defensive programming. - a pipe does not separate messages like a datagram socket does. If you get a burst of events and nldev writes them all to the pipe, nldev-handler won't be able to separate them. You need a message terminator. In s6-uevent-listener, I simply used an extra \0 as a message terminator. If you want to do the same: * line 225: iov.iov_len = sizeof(buf)-1; * insert after line 273: buf[len++] = 0; - do you really mean to set the kernel buffer to 128 MB ?
handler helper code: http://git.alpinelinux.org/cgit/ncopa/nldev/tree/nldev-handler.c
More comments later ;) -- Laurent _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
