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 05/17/2011 04:22 PM, Greg KH wrote: >> On Tue, May 17, 2011 at 10:56:03PM +0200, Alessio Igor Bogani wrote: >>> This work was supported by a hardware donation from the CE Linux Forum. [...] >> Please explain why you make a change, not just who sponsored the change, >> that's not very interesting to developers. You are right. I apologize. This patch is a missing piece (not essential it is only a further little optimization) of this little patchset: https://lkml.org/lkml/2011/4/16/48 Unfortunately I forgot to include this patch in the series (my first error) then I avoided explaining the changes because I had thought that those were already enough explained in the cover-letter of the patchset (my second error). Sorry for my mistakes. Is this better? Subject: [PATCH] module: Use binary search in lookup_symbol() 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. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani <abog...@kernel.org> --- kernel/module.c | 7 ++----- 1 files changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 1e2b657..795bdc7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2055,11 +2055,8 @@ static const struct kernel_symbol *lookup_symbol(const char *name, const struct kernel_symbol *start, const struct kernel_symbol *stop) { - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; + return bsearch(name, start, stop - start, + sizeof(struct kernel_symbol), cmp_name); } static int is_exported(const char *name, unsigned long value, -- Thank you very much! Ciao, Alessio -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
