# git rev-parse -q --verify 80d47f5de5e311cbc0d01ebb6ee684e8f4c196c6^{commit}
80d47f5de5e311cbc0d01ebb6ee684e8f4c196c6
already have revision, skipping fetch
# git checkout -q -f -B kisskb 80d47f5de5e311cbc0d01ebb6ee684e8f4c196c6
# git clean -qxdf
# < git log -1
# commit 80d47f5de5e311cbc0d01ebb6ee684e8f4c196c6
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Thu Feb 17 08:57:47 2022 -0800
# 
#     mm: don't try to NUMA-migrate COW pages that have other uses
#     
#     Oded Gabbay reports that enabling NUMA balancing causes corruption with
#     his Gaudi accelerator test load:
#     
#      "All the details are in the bug, but the bottom line is that somehow,
#       this patch causes corruption when the numa balancing feature is
#       enabled AND we don't use process affinity AND we use GUP to pin pages
#       so our accelerator can DMA to/from system memory.
#     
#       Either disabling numa balancing, using process affinity to bind to
#       specific numa-node or reverting this patch causes the bug to
#       disappear"
#     
#     and Oded bisected the issue to commit 09854ba94c6a ("mm: do_wp_page()
#     simplification").
#     
#     Now, the NUMA balancing shouldn't actually be changing the writability
#     of a page, and as such shouldn't matter for COW.  But it appears it
#     does.  Suspicious.
#     
#     However, regardless of that, the condition for enabling NUMA faults in
#     change_pte_range() is nonsensical.  It uses "page_mapcount(page)" to
#     decide if a COW page should be NUMA-protected or not, and that makes
#     absolutely no sense.
#     
#     The number of mappings a page has is irrelevant: not only does GUP get a
#     reference to a page as in Oded's case, but the other mappings migth be
#     paged out and the only reference to them would be in the page count.
#     
#     Since we should never try to NUMA-balance a page that we can't move
#     anyway due to other references, just fix the code to use 'page_count()'.
#     Oded confirms that that fixes his issue.
#     
#     Now, this does imply that something in NUMA balancing ends up changing
#     page protections (other than the obvious one of making the page
#     inaccessible to get the NUMA faulting information).  Otherwise the COW
#     simplification wouldn't matter - since doing the GUP on the page would
#     make sure it's writable.
#     
#     The cause of that permission change would be good to figure out too,
#     since it clearly results in spurious COW events - but fixing the
#     nonsensical test that just happened to work before is obviously the
#     CorrectThing(tm) to do regardless.
#     
#     Fixes: 09854ba94c6a ("mm: do_wp_page() simplification")
#     Link: https://bugzilla.kernel.org/show_bug.cgi?id=215616
#     Link: https://lore.kernel.org/all/CAFCwf10eNmwq2wD71xjUhqkvv5+_pJMR1nPug2RqNDcFT4H86Q@mail.gmail.com/
#     Reported-and-tested-by: Oded Gabbay <oded.gabbay@gmail.com>
#     Cc: David Hildenbrand <david@redhat.com>
#     Cc: Peter Xu <peterx@redhat.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-ld --version
# < git log --format=%s --max-count=1 80d47f5de5e311cbc0d01ebb6ee684e8f4c196c6
# < make -s -j 48 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-  allmodconfig
# Added to kconfig CONFIG_BUILD_DOCSRC=n
# Added to kconfig CONFIG_MODULE_SIG=n
# Added to kconfig CONFIG_SAMPLES=n
# < make -s -j 48 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-  help
# make -s -j 48 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-  olddefconfig
# make -s -j 48 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/xtensa-linux/bin/xtensa-linux-  
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:11.18-14.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x0: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:15.23-18.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x400000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:19.23-22.6: Warning (unit_address_format): /soc/flash@08000000/partition@0xa00000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:23.23-26.6: Warning (unit_address_format): /soc/flash@08000000/partition@0xfe0000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-4m.dtsi:11.18-14.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x0: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-4m.dtsi:15.23-18.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x3f0000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:11.18-14.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x0: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:15.24-18.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x6000000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:19.24-22.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x6800000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:23.24-26.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x7fe0000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:11.18-14.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x0: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:15.24-18.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x6000000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:19.24-22.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x6800000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi:23.24-26.6: Warning (unit_address_format): /soc/flash@00000000/partition@0x7fe0000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:11.18-14.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x0: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:15.23-18.6: Warning (unit_address_format): /soc/flash@08000000/partition@0x400000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:19.23-22.6: Warning (unit_address_format): /soc/flash@08000000/partition@0xa00000: unit name should not have leading "0x"
/kisskb/src/arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi:23.23-26.6: Warning (unit_address_format): /soc/flash@08000000/partition@0xfe0000: unit name should not have leading "0x"
WARNING: modpost: vmlinux.o(.text.unlikely+0x4540): Section mismatch in reference from the function __trace_event_discard_commit() to the variable .init.data:initcall_level_names
The function __trace_event_discard_commit() references
the variable __initdata initcall_level_names.
This is often because __trace_event_discard_commit lacks a __initdata 
annotation or the annotation of initcall_level_names is wrong.

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14410): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14428): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14440): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14458): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14470): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14488): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x144a0): Section mismatch in reference from the variable qed_mfw_legacy_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_legacy_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x144f0): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14508): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14520): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14538): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14550): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14568): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14580): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qed/qed.o(.data+0x14598): Section mismatch in reference from the variable qed_mfw_ext_maps to the variable .init.rodata:qed_mfw_legacy_bb_100g
The variable qed_mfw_ext_maps references
the variable __initconst qed_mfw_legacy_bb_100g
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x4790): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x47a8): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x47c0): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x47d8): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x47f0): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x4808): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: modpost: drivers/net/ethernet/qlogic/qede/qede.o(.data+0x4820): Section mismatch in reference from the variable qede_forced_speed_maps to the variable .init.rodata:qede_forced_speed_100000
The variable qede_forced_speed_maps references
the variable __initconst qede_forced_speed_100000
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Completed OK
# rm -rf /kisskb/build/linus_xtensa-allmodconfig_xtensa-gcc11
# Build took: 0:23:06.666113