From: Michael Ellerman <mpe@ellerman.id.au>
To: <linuxppc-dev@lists.ozlabs.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>,
Pingfan Liu <piliu@redhat.com>,
Pingfan Liu <kernelfans@gmail.com>
Subject: [RFC PATCH 2/5] powerpc/smp: Increase nr_cpu_ids to include the boot CPU
Date: Fri, 29 Dec 2023 23:01:04 +1100 [thread overview]
Message-ID: <20231229120107.2281153-2-mpe@ellerman.id.au> (raw)
In-Reply-To: <20231229120107.2281153-1-mpe@ellerman.id.au>
If nr_cpu_ids is too low to include the boot CPU adjust nr_cpu_ids
upward. Otherwise the kernel will BUG when trying to allocate a paca
for the boot CPU and fail to boot.
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/kernel/prom.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 58e80076bed5..77364729a1b6 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -381,6 +381,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
nr_cpu_ids);
}
+ if (boot_cpuid >= nr_cpu_ids) {
+ set_nr_cpu_ids(min(CONFIG_NR_CPUS, ALIGN(boot_cpuid + 1, nthreads)));
+ pr_warn("Boot CPU %d >= nr_cpu_ids, adjusted nr_cpu_ids to %d\n",
+ boot_cpuid, nr_cpu_ids);
+ }
+
/*
* PAPR defines "logical" PVR values for cpus that
* meet various levels of the architecture:
--
2.43.0
next prev parent reply other threads:[~2023-12-29 12:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-29 12:01 [RFC PATCH 1/5] powerpc/smp: Adjust nr_cpu_ids to cover all threads of a core Michael Ellerman
2023-12-29 12:01 ` Michael Ellerman [this message]
2023-12-29 12:01 ` [RFC PATCH 3/5] powerpc/smp: Lookup avail once per device tree node Michael Ellerman
2023-12-29 12:01 ` [RFC PATCH 4/5] powerpc/smp: Factor out assign_threads() Michael Ellerman
2024-01-02 4:34 ` Aneesh Kumar K.V
2024-02-14 13:10 ` Michael Ellerman
2023-12-29 12:01 ` [RFC PATCH 5/5] powerpc/smp: Remap boot CPU onto core 0 if >= nr_cpu_ids Michael Ellerman
2023-12-29 12:07 ` Michael Ellerman
2024-01-02 0:51 ` Pingfan Liu
2024-02-13 20:16 ` Wen Xiong
2024-01-02 4:46 ` Aneesh Kumar K.V
2024-02-09 15:56 ` Jiri Bohac
2024-02-14 13:12 ` Michael Ellerman
2024-02-15 13:00 ` [RFC PATCH 1/5] powerpc/smp: Adjust nr_cpu_ids to cover all threads of a core Michael Ellerman
2024-02-16 2:42 ` Pingfan Liu
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=20231229120107.2281153-2-mpe@ellerman.id.au \
--to=mpe@ellerman.id.au \
--cc=hbathini@linux.ibm.com \
--cc=kernelfans@gmail.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=piliu@redhat.com \
/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;
as well as URLs for NNTP newsgroup(s).