Re: [PATCH] fs: add FD_CLOFORK and O_CLOFORK

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Le samedi 07 mai 2011 Ã 12:49 +0800, Changli Gao a Ãcrit :
> 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@xxxxxxxxx>


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 ]



--
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux