Re: [PATCH] module: Use binary search in lookup_symbol()

2011-05-18 Thread Christoph Hellwig
On Tue, May 17, 2011 at 04:33:07PM -0700, Tim Bird wrote: That said, I can answer Greg's question. This is to speed up the symbol resolution on module loading. The last numbers I saw showed a reduction of about 15-20% for the module load time, for large-ish modules. Of course this is highly

Re: [PATCH] module: Use binary search in lookup_symbol()

2011-05-18 Thread Dirk Behme
On 17.05.2011 22:56, Alessio Igor Bogani wrote: This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Boganiabog...@kernel.org --- kernel/module.c |7 ++- 1 files changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/module.c

Re: [PATCH] module: Use binary search in lookup_symbol()

2011-05-18 Thread Tim Bird
On 05/18/2011 12:54 AM, Christoph Hellwig wrote: On Tue, May 17, 2011 at 04:33:07PM -0700, Tim Bird wrote: That said, I can answer Greg's question. This is to speed up the symbol resolution on module loading. The last numbers I saw showed a reduction of about 15-20% for the module load

[no subject]

2011-05-18 Thread Alessio Igor Bogani
Dear Mr. Bird, Dear Mr. Kroah-Hartman, Sorry for my very bad English. 2011/5/18 Tim Bird tim.b...@am.sony.com: [...] Alessio - do you have any timings you can share for the speedup? You can find a little benchmark using ftrace at end of this email: https://lkml.org/lkml/2011/4/5/341 On

Re: your mail

2011-05-18 Thread Greg KH
On Wed, May 18, 2011 at 08:55:25PM +0200, Alessio Igor Bogani wrote: Dear Mr. Bird, Dear Mr. Kroah-Hartman, Sorry for my very bad English. 2011/5/18 Tim Bird tim.b...@am.sony.com: [...] Alessio - do you have any timings you can share for the speedup? You can find a little benchmark

Re: [PATCH] module: Use binary search in lookup_symbol()

2011-05-18 Thread Greg KH
On Wed, May 18, 2011 at 10:00:12AM -0700, Tim Bird wrote: On 05/18/2011 12:54 AM, Christoph Hellwig wrote: On Tue, May 17, 2011 at 04:33:07PM -0700, Tim Bird wrote: That said, I can answer Greg's question. This is to speed up the symbol resolution on module loading. The last numbers I

Re: your mail

2011-05-18 Thread Alessio Igor Bogani
Dear Mr. Kroah-Hartman, 2011/5/18 Greg KH g...@kroah.com: [...] Care to resend it without all the stuff above so someone (Rusty I guess) can apply it? Sure! It'll follow in few minutes. Thank you very much! Ciao, Alessio -- To unsubscribe from this list: send the line unsubscribe

[PATCH] module: Use binary search in lookup_symbol()

2011-05-18 Thread Alessio Igor Bogani
The function is_exported() with its helper function lookup_symbol() are used to verify if a provided symbol is effectively exported by the kernel or by the modules. Now that both have their symbols sorted we can replace a linear search with a binary search which provide a considerably speed-up.

module boot time (was Re: [PATCH] module: Use binary search in lookup_symbol())

2011-05-18 Thread Tim Bird
On 05/18/2011 12:21 PM, Greg KH wrote: On Wed, May 18, 2011 at 10:00:12AM -0700, Tim Bird wrote: Carmelo Amoroso reported some good performance gains in this presentation: http://elinux.org/images/1/18/C_AMOROSO_Fast_lkm_loader_ELC-E_2009.pdf (See slide 22). He doesn't report the overall

Re: module boot time (was Re: [PATCH] module: Use binary search in lookup_symbol())

2011-05-18 Thread Greg KH
On Wed, May 18, 2011 at 02:10:15PM -0700, Tim Bird wrote: And why do people overly care for the load time? To reduce overall boot time. To reduce it even more, build the modules into the kernel :) That's what I do most of the time. For some projects, it is useful to build certain