27 Jan
2021
27 Jan
'21
7:01 a.m.
At Mon, 27 Jul 2020 12:57:59 -0600, Warner Losh <imp(a)bsdimp.com> wrote:
Subject: [TUHS] reboot(2) system call
I've done some research for a friend about when the reboot() system call
was added, and how it related to the sync, sync, sync dance.
https://bsdimp.blogspot.com/2020/07/when-unix-learned-to-reboot2.html
may be of interest. Please do let me know if I've gotten something wrong...
I've definitely experienced the second "sync" blocking until the first
was done. Once upon a time I remembered exactly why that happened, but
I no longer do.
The lore I was told at the time was that you alwasy ran three and that
it didn't matter if they were all on the same line with semicolons or
not because of the very fact that the second one would block.
The third one was just for superstitious good luck, and just in case
there was a process still running and writing to a filesystem.
--
Greg A. Woods <gwoods(a)acm.org>
Kelowna, BC +1 250 762-7675 RoboHack <woods(a)robohack.ca>
Planix, Inc. <woods(a)planix.com> Avoncote Farms <woods(a)avoncote.ca>