Messages in this thread | | | Subject | Re: [PATCH] fs: add FD_CLOFORK and O_CLOFORK | From | Eric Dumazet <> | Date | Sat, 07 May 2011 07:25:45 +0200 |
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Le samedi 07 mai 2011 à 12:49 +0800, Changli Gao a écrit : > If FD_CLOFORK is 1, when a fork occurs, the corresponding file descriptor > will be closed for the child process. IOW, the file descriptor isn't > inheritable. > > FD_CLOFORK is used as IBM does.
Is it part of a standard, and what could be the use for such thing ? Why had we wait 2011 to add it in linux ?
> > O_CLOFORK is also added to avoid the additional fcntl(2) after open(2). > > Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Your implementation has some peformance implication.
close_on_exec and close_on_fork bit for a given fd would be on separate cache lines. So you add a cost on threaded programs for open()/close()
[ Yes, we apparently clear close_on_exec bit in close()... we could let it untouched and make flush_old_files() aware of that ]
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