Go to file
Srikar Dronamraju c47f892d7a powerpc/smp: Reintroduce cpu_core_mask
Daniel reported that with Commit 4ca234a9cb ("powerpc/smp: Stop
updating cpu_core_mask") QEMU was unable to set single NUMA node SMP
topologies such as:
 -smp 8,maxcpus=8,cores=2,threads=2,sockets=2
 i.e he expected 2 sockets in one NUMA node.

The above commit helped to reduce boot time on Large Systems for
example 4096 vCPU single socket QEMU instance. PAPR is silent on
having more than one socket within a NUMA node.

cpu_core_mask and cpu_cpu_mask for any CPU would be same unless the
number of sockets is different from the number of NUMA nodes.

One option is to reintroduce cpu_core_mask but use a slightly
different method to arrive at the cpu_core_mask. Previously each CPU's
chip-id would be compared with all other CPU's chip-id to verify if
both the CPUs were related at the chip level. Now if a CPU 'A' is
found related / (unrelated) to another CPU 'B', all the thread
siblings of 'A' and thread siblings of 'B' are automatically marked as
related / (unrelated).

Also if a platform doesn't support ibm,chip-id property, i.e its
cpu_to_chip_id returns -1, cpu_core_map holds a copy of
cpu_cpu_mask().

Fixes: 4ca234a9cb ("powerpc/smp: Stop updating cpu_core_mask")
Reported-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210415120934.232271-2-srikar@linux.vnet.ibm.com
2021-04-17 10:40:51 +10:00
Documentation powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall 2021-04-14 23:04:07 +10:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch powerpc/smp: Reintroduce cpu_core_mask 2021-04-17 10:40:51 +10:00
block block: Discard page cache of zone reset target range 2021-03-11 11:49:25 -07:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto crypto: mips/poly1305 - enable for all MIPS processors 2021-03-08 11:52:17 +01:00
drivers macintosh/via-pmu: Fix build warning 2021-04-16 23:57:51 +10:00
fs Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
include signal: Add unsafe_get_compat_sigset() 2021-04-03 21:22:18 +11:00
init Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel prctl: fix PR_SET_MM_AUXV kernel stack leak 2021-03-14 14:33:27 -07:00
lib lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data() 2021-04-14 23:04:44 +10:00
mm Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
net NFS Client Bugfixes for Linux 5.10-rc3 2021-03-12 14:19:35 -08:00
samples Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2021-03-09 17:15:56 -08:00
scripts kbuild: fix ld-version.sh to not be affected by locale 2021-03-13 11:12:13 +09:00
security Revert 95ebabde38 ("capabilities: Don't allow writing ambiguous v3 file capabilities") 2021-03-12 15:27:14 -06:00
sound ALSA: hda/hdmi: Cancel pending works before suspend 2021-03-10 12:52:01 +01:00
tools selftests/powerpc: Suggest memtrace instead of /dev/mem for ci memory 2021-04-08 21:17:44 +10:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
Makefile Linux 5.12-rc3 2021-03-14 14:41:02 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.