Patch "x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs" has been added to the 4.3-stable tree
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This is a note to let you know that I've just added the patch titled
x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs
to the 4.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-smpboot-re-enable-init_udelay-0-by-default-on-modern-cpus.patch
and it can be found in the queue-4.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
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From
656279a1f3b210cf48ccc572fd7c6b8e2250be77Mon Sep 17 00:00:00 2001
From: Len Brown <[email protected]>
Date: Sun, 22 Nov 2015 18:16:15 -0500
Subject: x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs
From: Len Brown <[email protected]>
commit 656279a1f3b210cf48ccc572fd7c6b8e2250be77 upstream.
commit f1ccd249319e allowed the cmdline "cpu_init_udelay=" to work with all values, including the default of 10000.
But in setting the default of 10000, it over-rode the code that sets the delay 0 on modern processors.
Also, tidy up use of INT/UINT.
--- arch/x86/kernel/smpboot.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
arch/x86/kernel/smpboot.c +5 -4
@@ -509,7 +509,7 @@ void __inquire_remote_apic(int apicid)*/ #define UDELAY_10MS_DEFAULT 10000 -static unsigned int init_udelay =INT_MAX ; +static unsigned int init_udelay =UINT_MAX ;static int __init cpu_init_udelay (char *str) {
@@ -522,14 +522,15 @@ early_param("cpu_init_udelay", cpu_init_static void __init smp_quirk_init_udelay (void ) {/* if cmdline changed it from default, leave it alone */ -if (init_udelay !=INT_MAX ) +if (init_udelay !=UINT_MAX )return ;/* if modern processor, use no delay */ if (((boot_cpu_data.x86_vendor ==X86_VENDOR_INTEL ) && (boot_cpu_data.x86 ==6 )) || - ((boot_cpu_data.x86_vendor ==X86_VENDOR_AMD ) && (boot_cpu_data.x86 >=0xF ))) + ((boot_cpu_data.x86_vendor ==X86_VENDOR_AMD ) && (boot_cpu_data.x86 >=0xF ))) { init_udelay =0 ; - +return ; + }/* else, use legacy delay */ init_udelay =UDELAY_10MS_DEFAULT ; }
Patches currently in stable-queue which might be from [email protected] are
queue-4.3/x86-smpboot-re-enable-init_udelay-0-by-default-on-modern-cpus.patch