[PATCHv9 0/2] enable nr_cpus for powerpc

Pingfan Liu piliu at redhat.com
Tue Oct 17 13:28:04 AEDT 2023

From: Pingfan Liu <kernelfans at gmail.com>

Since my last v4 [1], the code has undergone great changes. The paca[]
array has been reorganized and indexed by paca_ptrs[], which
dramatically decreases the memory consumption even if there are many
unpresent cpus in the middle.

However, reordering the logical cpu numbers can further decrease the
size of paca_ptrs[] in the kdump case. These two patches rotate-shifts
the cpu's sequence number in the device tree to obtain the logical cpu

[1]: https://lore.kernel.org/linuxppc-dev/1520829790-14029-1-git-send-email-kernelfans@gmail.com/
v8 -> v9
  put aside [3-5/5] in v8 for the time being, which complicates the code.
  optimize out some unnecessary initialization according to Hari's

Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Nicholas Piggin <npiggin at gmail.com>
Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
Cc: Wen Xiong <wenxiong at us.ibm.com>
Cc: Baoquan He <bhe at redhat.com>
Cc: Ming Lei <ming.lei at redhat.com>
Cc: Sourabh Jain <sourabhjain at linux.ibm.com>
Cc: Hari Bathini <hbathini at linux.ibm.com>
Cc: kexec at lists.infradead.org
To: linuxppc-dev at lists.ozlabs.org

Pingfan Liu (2):
  powerpc/setup : Enable boot_cpu_hwid for PPC32
  powerpc/setup: Loosen the mapping between cpu logical id and its seq
    in dt

 arch/powerpc/include/asm/smp.h     |  2 +-
 arch/powerpc/kernel/prom.c         | 26 +++++----
 arch/powerpc/kernel/setup-common.c | 86 +++++++++++++++++++++++-------
 3 files changed, 83 insertions(+), 31 deletions(-)


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