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 1/5] powerpc/smp: Adjust nr_cpu_ids to cover all threads of a core
Date: Fri, 29 Dec 2023 23:01:03 +1100 [thread overview]
Message-ID: <20231229120107.2281153-1-mpe@ellerman.id.au> (raw)
If nr_cpu_ids is too low to include at least all the threads of a single
core adjust nr_cpu_ids upwards. This avoids triggering odd bugs in code
that assumes all threads of a core are available.
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 0b5878c3125b..58e80076bed5 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -375,6 +375,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
if (IS_ENABLED(CONFIG_PPC64))
boot_cpu_hwid = be32_to_cpu(intserv[found_thread]);
+ if (nr_cpu_ids % nthreads != 0) {
+ set_nr_cpu_ids(ALIGN(nr_cpu_ids, nthreads));
+ pr_warn("nr_cpu_ids was not a multiple of threads_per_core, adjusted to %d\n",
+ nr_cpu_ids);
+ }
+
/*
* PAPR defines "logical" PVR values for cpus that
* meet various levels of the architecture:
--
2.43.0
next reply other threads:[~2023-12-29 12:02 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-29 12:01 Michael Ellerman [this message]
2023-12-29 12:01 ` [RFC PATCH 2/5] powerpc/smp: Increase nr_cpu_ids to include the boot CPU Michael Ellerman
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
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