From: "tip-bot for Kirill A. Shutemov" <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, mingo@kernel.org, peterz@infradead.org,
tglx@linutronix.de, torvalds@linux-foundation.org,
kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org
Subject: [tip:x86/build] x86/kconfig: Bump default NR_CPUS from 8 to 64 for 64-bit configuration
Date: Fri, 8 May 2015 06:29:27 -0700 [thread overview]
Message-ID: <tip-c5c19941ad1bb18f010ae47f1db333c00b276d55@git.kernel.org> (raw)
In-Reply-To: <1431080745-19792-1-git-send-email-kirill.shutemov@linux.intel.com>
Commit-ID: c5c19941ad1bb18f010ae47f1db333c00b276d55
Gitweb: http://git.kernel.org/tip/c5c19941ad1bb18f010ae47f1db333c00b276d55
Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
AuthorDate: Fri, 8 May 2015 13:25:45 +0300
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 8 May 2015 12:58:56 +0200
x86/kconfig: Bump default NR_CPUS from 8 to 64 for 64-bit configuration
Default NR_CPUS==8 is not enough to cover high-end desktop
configuration: Haswell-E has upto 16 threads.
Let's increase default NR_CPUS to 64 on 64-bit configuration.
With this value CPU bitmask will still fit into one unsigned long.
Default for 32-bit configuration is still 8: it's unlikely
anybody will run 32-bit kernels on modern hardware.
As an alternative we could bump NR_CPUS to 128 to cover all
dual-processor servers with some margin.
For reference: Debian and Suse build their kernels with
NR_CPUS==512, Fedora -- 1024.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431080745-19792-1-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/Kconfig | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 226d569..83cd1c7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -851,7 +851,8 @@ config NR_CPUS
default "1" if !SMP
default "8192" if MAXSMP
default "32" if SMP && X86_BIGSMP
- default "8" if SMP
+ default "8" if SMP && X86_32
+ default "64" if SMP
---help---
This allows you to specify the maximum number of CPUs which this
kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
next prev parent reply other threads:[~2015-05-08 13:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-08 10:25 [PATCH] x86: bump default NR_CPUS for 64-bit configuration Kirill A. Shutemov
2015-05-08 13:29 ` tip-bot for Kirill A. Shutemov [this message]
2015-05-12 17:57 ` Josh Boyer
2015-05-13 7:27 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tip-c5c19941ad1bb18f010ae47f1db333c00b276d55@git.kernel.org \
--to=tipbot@zytor.com \
--cc=akpm@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox