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Piccoli" To: linux-doc@vger.kernel.org, corbet@lwn.net Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, rdunlap@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, kernel@gpiccoli.net, kernel-dev@igalia.com, "Guilherme G. Piccoli" , Changwoo Min Subject: [PATCH] docs: Document possible_cpus parameter Date: Sat, 3 Feb 2024 12:21:13 -0300 Message-ID: <20240203152208.1461293-1-gpiccoli@igalia.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789891726746936552 X-GMAIL-MSGID: 1789891726746936552 The number of possible CPUs is set be kernel in early boot time through some discovery mechanisms, like ACPI in x86. We have a parameter both in x86 and S390 to override that - there are some cases of BIOSes exposing more possible CPUs than the available ones, so this parameter is a good testing mechanism, but for some reason wasn't mentioned so far in the kernel parameters guide - let's fix that. Cc: Changwoo Min Signed-off-by: Guilherme G. Piccoli Reviewed-by: Randy Dunlap --- Documentation/admin-guide/kernel-parameters.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 31b3a25680d0..e553740190ea 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4644,6 +4644,11 @@ may be specified. Format: ,.... + possible_cpus= [SMP,S390,X86] + Format: + Set the number of possible CPUs, overriding the + regular discovery mechanisms (such as ACPI/FW, etc). + powersave=off [PPC] This option disables power saving features. It specifically disables cpuidle and sets the platform machine description specific power_save