linux-kernel - [PATCH] Drivers: hv: Kconfig: select CPUMASK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1708092603-14504-1-git-send-email-ssengar@linux.microsoft.com>
Date: Fri, 16 Feb 2024 06:10:03 -0800
From: Saurabh Sengar <ssengar@...ux.microsoft.com>
To: kys@...rosoft.com,
	haiyangz@...rosoft.com,
	wei.liu@...nel.org,
	decui@...rosoft.com,
	linux-hyperv@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: ssengar@...rosoft.com
Subject: [PATCH] Drivers: hv: Kconfig: select CPUMASK_OFFSTACK for Hyper-V

CPUMASK_OFFSTACK must be set to have NR_CPUS_RANGE_END value greater than
512, which eventually allows NR_CPUS > 512.

CPUMASK_OFFSTACK can also be enabled by setting MAXSMP=y, but that will
set NR_CPUS=8192. This is not accurate for Hyper-V, because maximum number
of vCPU supported by Hyper-V today is 2048. Thus, enabling MAXSMP increase
the vmlinux size unnecessary.

This option allows NR_CPUS=2048 which saves around 1MB of vmlinux size for
Hyper-V.

Signed-off-by: Saurabh Sengar <ssengar@...ux.microsoft.com>
---
 drivers/hv/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 0024210..bc3f496 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -9,6 +9,7 @@ config HYPERV
 	select PARAVIRT
 	select X86_HV_CALLBACK_VECTOR if X86
 	select OF_EARLY_FLATTREE if OF
+	select CPUMASK_OFFSTACK
 	help
 	  Select this option to run Linux as a Hyper-V client operating
 	  system.
-- 
1.8.3.1