Messages in this thread | | | Date | Fri, 8 May 2015 10:32:51 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH 2/2] x86: speed cpu_up by quirking cpu_init_udelay |
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On Fri, May 08, 2015 at 02:37:55AM -0400, Len Brown wrote: > From: Len Brown <len.brown@intel.com> > > Modern processor familes are on a white-list to remove > the costly cpu_init_udelay 10000. Unknown processor families > get the traditional 10ms delay in cpu_up(). > > This seemed more efficient than forcing modern processors > to exhaustively search a black-list having all the old > processor families that should have a 10ms delay. > For not only are new processor familes infrequently added, > the white list also allows a delay other than 0, if needed. > > Signed-off-by: Len Brown <len.brown@intel.com> > --- > arch/x86/kernel/smpboot.c | 37 +++++++++++++++++++++++++++++++++++-- > 1 file changed, 35 insertions(+), 2 deletions(-)
...
> +static void __init smp_quirk_init_udelay(void) > +{ > + const struct x86_cpu_id *id; > + unsigned int new_udelay; > + > + id = x86_match_cpu(init_udelay_ids); > + if (id == NULL) > + return; /* if no match, keep default */ > + > + if (init_udelay != UDELAY_10MS_DEFAULT) > + return; /* if cmdline changed from default, leave it alone */ > + > + new_udelay = (unsigned long) id->driver_data; > + pr_debug("cpu_init_udelay quirk to %d, was %d", new_udelay, init_udelay);
Can we make this printk(KERN_DEBUG please?
I'd like to be able to slap "debug" on the command line and not recompile the kernel. And no, dyndbg="file smpboot.c +p" or whatever the syntax is, simply doesn't scale if I want to see all debug messages from early boot.
Thanks.
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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