Messages in this thread | | | Date | Sun, 3 Jun 2007 08:43:22 +0200 | From | Ingo Molnar <> | Subject | Re: [patch 2/2] ufd v1 - use unsequential O(1) fdmap |
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* Davide Libenzi <davidel@xmailserver.org> wrote:
> This patch plugs the extended fdmap into the kernel. At the moment, this > is done only through sys_dup2() and F_DUPFD. > The base value for the unsequential file descriptor allocation is (at the > moment) set to FD_UNSEQ_BASE (defined in asm-generic/fcntl.h):
really nice stuff! :-)
> #define FD_UNSEQ_BASE (1U << 28) > #define FD_UNSEQ_ALLOC (1U << 30)
i'm wondering, why not use (1 << 30) both as the base and as the flag? That would make integration of the new fd space 'seemless' in terms of dup2() use.
> It'd be possible to add a new O_UNSEQFD flag to open(2) and make > sys_open() to allocate the new descriptor inside the unsequential map.
yeah, please do that now - lets not leave any incomplete areas. We've too often made the mistake of not pushing through new APIs consistently enough.
I'd also suggest a new sys_socket2() call that takes a 'flags' parameter as well - because one primary user of this facility will be networking servers. (O_UNSEQFD would make sense for it and O_NDELAY - currently network apps that want to set O_NDELAY need to do it with an extra fcntl() - while they could already indicate this in the sys_socket() call, if it were closer to sys_open() semantics)
in any case, your patch is looking really good and already deserves an ack!
Acked-by: Ingo Molnar <mingo@elte.hu>
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