[PATCH] Quieten cache information at boot

[PATCH] Quieten cache information at boot

[Anton Blanchard]

After 6 years the ppc64 kernel still thinks its important to tell me my
cache line size is 0x80 bytes. I think most people who care know that by
now. The rest probably cant even understand the hex output.

Since we might have misconfigured firmware or cpus that have a linesize
that isnt 128 bytes, I still print it out for those cases. If people
would prefer to remove it completely, lets do it.

Also for lpar remove the htab_address printout since its not used.

Anton
ppc64 boot log usability expert

Signed-off-by: Anton Blanchard <anton@samba.org>
---

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 008ab68..e413c49 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -426,11 +426,14 @@ void __init setup_system(void)
 	printk("-----------------------------------------------------\n");
 	printk("ppc64_pft_size                = 0x%lx\n", ppc64_pft_size);
 	printk("physicalMemorySize            = 0x%lx\n", lmb_phys_mem_size());
-	printk("ppc64_caches.dcache_line_size = 0x%x\n",
-	       ppc64_caches.dline_size);
-	printk("ppc64_caches.icache_line_size = 0x%x\n",
-	       ppc64_caches.iline_size);
-	printk("htab_address                  = 0x%p\n", htab_address);
+	if (ppc64_caches.dline_size != 0x80)
+		printk("ppc64_caches.dcache_line_size = 0x%x\n",
+		       ppc64_caches.dline_size);
+	if (ppc64_caches.iline_size != 0x80)
+		printk("ppc64_caches.icache_line_size = 0x%x\n",
+		       ppc64_caches.iline_size);
+	if (htab_address)
+		printk("htab_address                  = 0x%p\n", htab_address);
 	printk("htab_hash_mask                = 0x%lx\n", htab_hash_mask);
 #if PHYSICAL_START > 0
 	printk("physical_start                = 0x%x\n", PHYSICAL_START);

Re: [PATCH] Quieten cache information at boot

[Olof Johansson]

On Sun, Oct 14, 2007 at 02:33:17PM -0500, Anton Blanchard wrote:
> 
> After 6 years the ppc64 kernel still thinks its important to tell me my
> cache line size is 0x80 bytes. I think most people who care know that by
> now. The rest probably cant even understand the hex output.
> 
> Since we might have misconfigured firmware or cpus that have a linesize
> that isnt 128 bytes, I still print it out for those cases. If people
> would prefer to remove it completely, lets do it.

Let's just remove it completely. I have yet to see a bug because of it,
and we have 0x40 byte cache lines.

If anything, compare firmware setting to cputable one and print a warning.

Should maybe give them loglevels too, since you're touching them? I
suggest KERN_DEBUG -- if needed it's there in dmesg, and if you need it
on the console you can just add "debug" to the kernel command line.


-Olof

Re: [PATCH] Quieten cache information at boot

[Anton Blanchard]

 
Hi,

> Let's just remove it completely. I have yet to see a bug because of it,
> and we have 0x40 byte cache lines.

Yeah I completely support killing it too :)

> If anything, compare firmware setting to cputable one and print a warning.
> 
> Should maybe give them loglevels too, since you're touching them? I
> suggest KERN_DEBUG -- if needed it's there in dmesg, and if you need it
> on the console you can just add "debug" to the kernel command line.

I started playing with loglevels but theres some ordering issues since
the options to change loglevel (eg the "debug" boot option) doesnt get
parsed until later in a __setup function.

Anton

Re: [PATCH] Quieten cache information at boot

[Benjamin Herrenschmidt]

On Sun, 2007-10-14 at 14:33 -0500, Anton Blanchard wrote:
> After 6 years the ppc64 kernel still thinks its important to tell me my
> cache line size is 0x80 bytes. I think most people who care know that by
> now. The rest probably cant even understand the hex output.
> 
> Since we might have misconfigured firmware or cpus that have a linesize
> that isnt 128 bytes, I still print it out for those cases. If people
> would prefer to remove it completely, lets do it.
> 
> Also for lpar remove the htab_address printout since its not used.

Why not also make those KERN_DEBUG ?

Ben.

Re: [PATCH] Quieten cache information at boot

[Benjamin Herrenschmidt]

On Sun, 2007-10-14 at 15:14 -0500, Olof Johansson wrote:
> On Sun, Oct 14, 2007 at 02:33:17PM -0500, Anton Blanchard wrote:
> > 
> > After 6 years the ppc64 kernel still thinks its important to tell me my
> > cache line size is 0x80 bytes. I think most people who care know that by
> > now. The rest probably cant even understand the hex output.
> > 
> > Since we might have misconfigured firmware or cpus that have a linesize
> > that isnt 128 bytes, I still print it out for those cases. If people
> > would prefer to remove it completely, lets do it.
> 
> Let's just remove it completely. I have yet to see a bug because of it,
> and we have 0x40 byte cache lines.

I did have issues because of incorrect cache line sizes recently... this
printk was actually useful for me :-)

Ben.