[PATCH kernel 2/3] powerpc/llvm: Sample config for LLVM LTO

Alexey Kardashevskiy aik at ozlabs.ru
Fri Feb 11 13:31:24 AEDT 2022


The config is a copy of ppc64_defconfig with a few tweaks. This could be
a smaller config to merge into ppc64_defconfig but unfortunately
merger does not allow disabling already enabled options.

This is a command line to compile the kernel using the upstream llvm:

make -j64 O=/home/aik/pbuild/kernels-llvm/ \
 "KCFLAGS=-Wmissing-braces -Wno-array-bounds" \
 ARCH=powerpc LLVM_IAS=1 ppc64le_lto_defconfig CC=clang LLVM=1

Forces CONFIG_BTRFS_FS=y to make CONFIG_ZSTD_COMPRESS=y to fix:
ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(entropy_common.o at 5332)' and 'ld-temp.o'

because modules are linked with -mcmodel=large but the kernel uses -mcmodel=medium

Enables CONFIG_USERFAULTFD=y as otherwise vm_userfaultfd_ctx becomes
0 bytes long and clang sanitizer crashes as
https://bugs.llvm.org/show_bug.cgi?id=500375

Disables CONFIG_FTR_FIXUP_SELFTEST as it uses FTR_SECTION_ELSE with
conditional branches. There are other places like this and the following
patches address that.

Disables CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT as CONFIG_HAS_LTO_CLANG
depends on it being disabled. In order to avoid disabling way too many
options (like DYNAMIC_FTRACE/FUNCTION_TRACER), this converts
FTRACE_MCOUNT_USE_RECORDMCOUNT from def_bool to bool.

Note that even with this config there is a good chance that LTO
is going to fail linking vmlinux because of the "bc" problem.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/Makefile                    |   4 +
 arch/powerpc/configs/ppc64_lto_defconfig | 381 +++++++++++++++++++++++
 2 files changed, 385 insertions(+)
 create mode 100644 arch/powerpc/configs/ppc64_lto_defconfig

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 5f16ac1583c5..23f1ade8abc9 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -308,6 +308,10 @@ PHONY += ppc64le_defconfig
 ppc64le_defconfig:
 	$(call merge_into_defconfig,ppc64_defconfig,le)
 
+PHONY += ppc64le_lto_defconfig
+ppc64le_lto_defconfig:
+	$(call merge_into_defconfig,ppc64_lto_defconfig,le)
+
 PHONY += ppc64le_guest_defconfig
 ppc64le_guest_defconfig:
 	$(call merge_into_defconfig,ppc64_defconfig,le guest)
diff --git a/arch/powerpc/configs/ppc64_lto_defconfig b/arch/powerpc/configs/ppc64_lto_defconfig
new file mode 100644
index 000000000000..67f82b422b7d
--- /dev/null
+++ b/arch/powerpc/configs/ppc64_lto_defconfig
@@ -0,0 +1,381 @@
+CONFIG_SYSVIPC=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_NO_HZ=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_TASKSTATS=y
+CONFIG_TASK_DELAY_ACCT=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
+CONFIG_LOG_BUF_SHIFT=18
+CONFIG_LOG_CPU_MAX_BUF_SHIFT=13
+CONFIG_NUMA_BALANCING=y
+CONFIG_CGROUPS=y
+CONFIG_MEMCG=y
+CONFIG_CGROUP_SCHED=y
+CONFIG_CGROUP_FREEZER=y
+CONFIG_CPUSETS=y
+CONFIG_CGROUP_DEVICE=y
+CONFIG_CGROUP_CPUACCT=y
+CONFIG_CGROUP_PERF=y
+CONFIG_CGROUP_BPF=y
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_BPF_SYSCALL=y
+# CONFIG_COMPAT_BRK is not set
+CONFIG_PROFILING=y
+CONFIG_PPC64=y
+CONFIG_NR_CPUS=2048
+CONFIG_PPC_SPLPAR=y
+CONFIG_DTL=y
+CONFIG_PPC_SMLPAR=y
+CONFIG_IBMEBUS=y
+CONFIG_PPC_SVM=y
+CONFIG_PPC_MAPLE=y
+CONFIG_PPC_PASEMI=y
+CONFIG_PPC_PASEMI_IOMMU=y
+CONFIG_PPC_PS3=y
+CONFIG_PS3_DISK=m
+CONFIG_PS3_ROM=m
+CONFIG_PS3_FLASH=m
+CONFIG_PS3_LPM=m
+CONFIG_PPC_IBM_CELL_BLADE=y
+CONFIG_RTAS_FLASH=m
+CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
+CONFIG_CPU_FREQ_GOV_POWERSAVE=y
+CONFIG_CPU_FREQ_GOV_USERSPACE=y
+CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
+CONFIG_CPU_FREQ_PMAC64=y
+CONFIG_HZ_100=y
+CONFIG_PPC_TRANSACTIONAL_MEM=y
+CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
+CONFIG_CRASH_DUMP=y
+CONFIG_FA_DUMP=y
+CONFIG_IRQ_ALL_CPUS=y
+CONFIG_SCHED_SMT=y
+CONFIG_HOTPLUG_PCI=y
+CONFIG_HOTPLUG_PCI_RPA=m
+CONFIG_HOTPLUG_PCI_RPA_DLPAR=m
+CONFIG_PCCARD=y
+CONFIG_ELECTRA_CF=y
+CONFIG_VIRTUALIZATION=y
+CONFIG_KVM_BOOK3S_64=m
+CONFIG_KVM_BOOK3S_64_HV=m
+CONFIG_VHOST_NET=m
+CONFIG_KPROBES=y
+CONFIG_JUMP_LABEL=y
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+CONFIG_MODVERSIONS=y
+CONFIG_MODULE_SRCVERSION_ALL=y
+CONFIG_PARTITION_ADVANCED=y
+CONFIG_BINFMT_MISC=m
+CONFIG_MEMORY_HOTPLUG=y
+CONFIG_MEMORY_HOTREMOVE=y
+CONFIG_KSM=y
+CONFIG_TRANSPARENT_HUGEPAGE=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_XFRM_USER=m
+CONFIG_NET_KEY=m
+CONFIG_INET=y
+CONFIG_IP_MULTICAST=y
+CONFIG_IP_PNP=y
+CONFIG_IP_PNP_DHCP=y
+CONFIG_IP_PNP_BOOTP=y
+CONFIG_NET_IPIP=y
+CONFIG_SYN_COOKIES=y
+CONFIG_INET_AH=m
+CONFIG_INET_ESP=m
+CONFIG_INET_IPCOMP=m
+CONFIG_IPV6=y
+CONFIG_NETFILTER=y
+# CONFIG_NETFILTER_ADVANCED is not set
+CONFIG_BRIDGE=m
+CONFIG_NET_SCHED=y
+CONFIG_NET_CLS_BPF=m
+CONFIG_NET_CLS_ACT=y
+CONFIG_NET_ACT_BPF=m
+CONFIG_BPF_JIT=y
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_BLK_DEV_FD=y
+CONFIG_BLK_DEV_LOOP=y
+CONFIG_BLK_DEV_NBD=m
+CONFIG_BLK_DEV_RAM=y
+CONFIG_BLK_DEV_RAM_SIZE=65536
+CONFIG_VIRTIO_BLK=m
+CONFIG_BLK_DEV_SD=y
+CONFIG_CHR_DEV_ST=m
+CONFIG_BLK_DEV_SR=y
+CONFIG_CHR_DEV_SG=y
+CONFIG_SCSI_CONSTANTS=y
+CONFIG_SCSI_FC_ATTRS=y
+CONFIG_SCSI_CXGB3_ISCSI=m
+CONFIG_SCSI_CXGB4_ISCSI=m
+CONFIG_SCSI_BNX2_ISCSI=m
+CONFIG_BE2ISCSI=m
+CONFIG_SCSI_MPT2SAS=m
+CONFIG_SCSI_IBMVSCSI=y
+CONFIG_SCSI_IBMVFC=m
+CONFIG_SCSI_SYM53C8XX_2=m
+CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=0
+CONFIG_SCSI_IPR=y
+CONFIG_SCSI_QLA_FC=m
+CONFIG_SCSI_QLA_ISCSI=m
+CONFIG_SCSI_LPFC=m
+CONFIG_SCSI_VIRTIO=m
+CONFIG_SCSI_DH=y
+CONFIG_SCSI_DH_RDAC=m
+CONFIG_SCSI_DH_ALUA=m
+CONFIG_ATA=y
+CONFIG_SATA_AHCI=y
+CONFIG_SATA_SIL24=y
+CONFIG_SATA_MV=y
+CONFIG_SATA_SVW=y
+CONFIG_PATA_AMD=y
+CONFIG_PATA_MACIO=y
+CONFIG_ATA_GENERIC=y
+CONFIG_MD=y
+CONFIG_BLK_DEV_MD=y
+CONFIG_MD_LINEAR=y
+CONFIG_MD_RAID0=y
+CONFIG_MD_RAID1=y
+CONFIG_MD_RAID10=m
+CONFIG_MD_RAID456=m
+CONFIG_MD_MULTIPATH=m
+CONFIG_MD_FAULTY=m
+CONFIG_BLK_DEV_DM=y
+CONFIG_DM_CRYPT=m
+CONFIG_DM_SNAPSHOT=m
+CONFIG_DM_MIRROR=m
+CONFIG_DM_ZERO=m
+CONFIG_DM_MULTIPATH=m
+CONFIG_DM_MULTIPATH_QL=m
+CONFIG_DM_MULTIPATH_ST=m
+CONFIG_DM_UEVENT=y
+CONFIG_ADB_PMU=y
+CONFIG_PMAC_SMU=y
+CONFIG_WINDFARM=y
+CONFIG_WINDFARM_PM81=y
+CONFIG_WINDFARM_PM91=y
+CONFIG_WINDFARM_PM112=y
+CONFIG_WINDFARM_PM121=y
+CONFIG_BONDING=m
+CONFIG_DUMMY=m
+CONFIG_NETCONSOLE=y
+CONFIG_TUN=m
+CONFIG_VIRTIO_NET=m
+CONFIG_VORTEX=m
+CONFIG_ACENIC=m
+CONFIG_ACENIC_OMIT_TIGON_I=y
+CONFIG_PCNET32=m
+CONFIG_TIGON3=y
+CONFIG_BNX2X=m
+CONFIG_CHELSIO_T1=m
+CONFIG_BE2NET=m
+CONFIG_IBMVETH=m
+CONFIG_EHEA=m
+CONFIG_IBMVNIC=m
+CONFIG_E100=y
+CONFIG_E1000=y
+CONFIG_E1000E=y
+CONFIG_IXGB=m
+CONFIG_IXGBE=m
+CONFIG_I40E=m
+CONFIG_MLX4_EN=m
+CONFIG_MYRI10GE=m
+CONFIG_S2IO=m
+CONFIG_PASEMI_MAC=y
+CONFIG_NETXEN_NIC=m
+CONFIG_SUNGEM=y
+CONFIG_GELIC_NET=m
+CONFIG_GELIC_WIRELESS=y
+CONFIG_SPIDER_NET=m
+CONFIG_BROADCOM_PHY=m
+CONFIG_MARVELL_PHY=y
+CONFIG_PPP=m
+CONFIG_PPP_BSDCOMP=m
+CONFIG_PPP_DEFLATE=m
+CONFIG_PPPOE=m
+CONFIG_PPP_ASYNC=m
+CONFIG_PPP_SYNC_TTY=m
+CONFIG_INPUT_EVDEV=m
+CONFIG_INPUT_MISC=y
+CONFIG_INPUT_PCSPKR=m
+# CONFIG_SERIO_SERPORT is not set
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_ICOM=m
+CONFIG_SERIAL_JSM=m
+CONFIG_HVC_CONSOLE=y
+CONFIG_HVC_RTAS=y
+CONFIG_HVCS=m
+CONFIG_VIRTIO_CONSOLE=m
+CONFIG_IBM_BSR=m
+CONFIG_RAW_DRIVER=y
+CONFIG_I2C_CHARDEV=y
+CONFIG_I2C_AMD8111=y
+CONFIG_I2C_PASEMI=y
+CONFIG_FB=y
+CONFIG_FIRMWARE_EDID=y
+CONFIG_FB_OF=y
+CONFIG_FB_MATROX=y
+CONFIG_FB_MATROX_MILLENIUM=y
+CONFIG_FB_MATROX_MYSTIQUE=y
+CONFIG_FB_MATROX_G=y
+CONFIG_FB_MATROX_I2C=m
+CONFIG_FB_MATROX_MAVEN=m
+CONFIG_FB_RADEON=y
+CONFIG_FB_IBM_GXT4500=y
+CONFIG_FB_PS3=m
+CONFIG_LCD_CLASS_DEVICE=y
+# CONFIG_VGA_CONSOLE is not set
+CONFIG_FRAMEBUFFER_CONSOLE=y
+CONFIG_LOGO=y
+CONFIG_SOUND=m
+CONFIG_SND=m
+CONFIG_SND_OSSEMUL=y
+CONFIG_SND_MIXER_OSS=m
+CONFIG_SND_PCM_OSS=m
+CONFIG_SND_SEQUENCER=m
+CONFIG_SND_SEQ_DUMMY=m
+CONFIG_SND_SEQUENCER_OSS=m
+CONFIG_SND_POWERMAC=m
+CONFIG_SND_AOA=m
+CONFIG_SND_AOA_FABRIC_LAYOUT=m
+CONFIG_SND_AOA_ONYX=m
+CONFIG_SND_AOA_TAS=m
+CONFIG_SND_AOA_TOONIE=m
+CONFIG_HID_GYRATION=y
+CONFIG_HID_PANTHERLORD=y
+CONFIG_HID_PETALYNX=y
+CONFIG_HID_SAMSUNG=y
+CONFIG_HID_SUNPLUS=y
+CONFIG_USB_HIDDEV=y
+CONFIG_USB=y
+CONFIG_USB_MON=m
+CONFIG_USB_EHCI_HCD=y
+# CONFIG_USB_EHCI_HCD_PPC_OF is not set
+CONFIG_USB_OHCI_HCD=y
+CONFIG_USB_STORAGE=m
+CONFIG_USB_APPLEDISPLAY=m
+CONFIG_NEW_LEDS=y
+CONFIG_LEDS_CLASS=m
+CONFIG_LEDS_POWERNV=m
+CONFIG_INFINIBAND=m
+CONFIG_INFINIBAND_USER_MAD=m
+CONFIG_INFINIBAND_USER_ACCESS=m
+CONFIG_INFINIBAND_MTHCA=m
+CONFIG_INFINIBAND_CXGB4=m
+CONFIG_MLX4_INFINIBAND=m
+CONFIG_INFINIBAND_IPOIB=m
+CONFIG_INFINIBAND_IPOIB_CM=y
+CONFIG_INFINIBAND_SRP=m
+CONFIG_INFINIBAND_ISER=m
+CONFIG_EDAC=y
+CONFIG_EDAC_PASEMI=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_DS1307=y
+CONFIG_VIRTIO_PCI=m
+CONFIG_VIRTIO_BALLOON=m
+CONFIG_LIBNVDIMM=y
+CONFIG_RAS=y
+CONFIG_EXT2_FS=y
+CONFIG_EXT2_FS_XATTR=y
+CONFIG_EXT2_FS_POSIX_ACL=y
+CONFIG_EXT2_FS_SECURITY=y
+CONFIG_EXT4_FS=y
+CONFIG_EXT4_FS_POSIX_ACL=y
+CONFIG_EXT4_FS_SECURITY=y
+CONFIG_REISERFS_FS=m
+CONFIG_REISERFS_FS_XATTR=y
+CONFIG_REISERFS_FS_POSIX_ACL=y
+CONFIG_REISERFS_FS_SECURITY=y
+CONFIG_JFS_FS=m
+CONFIG_JFS_POSIX_ACL=y
+CONFIG_JFS_SECURITY=y
+CONFIG_XFS_FS=y
+CONFIG_XFS_POSIX_ACL=y
+CONFIG_BTRFS_FS=y
+CONFIG_BTRFS_FS_POSIX_ACL=y
+CONFIG_NILFS2_FS=m
+CONFIG_FS_DAX=y
+CONFIG_AUTOFS4_FS=m
+CONFIG_FUSE_FS=m
+CONFIG_OVERLAY_FS=m
+CONFIG_ISO9660_FS=y
+CONFIG_UDF_FS=m
+CONFIG_MSDOS_FS=y
+CONFIG_VFAT_FS=m
+CONFIG_PROC_KCORE=y
+CONFIG_TMPFS=y
+CONFIG_TMPFS_POSIX_ACL=y
+CONFIG_HUGETLBFS=y
+CONFIG_HFS_FS=m
+CONFIG_HFSPLUS_FS=m
+CONFIG_CRAMFS=m
+CONFIG_SQUASHFS=m
+CONFIG_SQUASHFS_XATTR=y
+CONFIG_SQUASHFS_LZO=y
+CONFIG_SQUASHFS_XZ=y
+CONFIG_NFS_FS=y
+CONFIG_NFS_V3_ACL=y
+CONFIG_NFS_V4=y
+CONFIG_ROOT_NFS=y
+CONFIG_NFSD=m
+CONFIG_NFSD_V3_ACL=y
+CONFIG_NFSD_V4=y
+CONFIG_CIFS=m
+CONFIG_CIFS_XATTR=y
+CONFIG_CIFS_POSIX=y
+CONFIG_NLS_DEFAULT="utf8"
+CONFIG_NLS_CODEPAGE_437=y
+CONFIG_NLS_ASCII=y
+CONFIG_NLS_ISO8859_1=y
+CONFIG_NLS_UTF8=y
+CONFIG_CRYPTO_TEST=m
+CONFIG_CRYPTO_PCBC=m
+CONFIG_CRYPTO_HMAC=y
+CONFIG_CRYPTO_CRC32C_VPMSUM=m
+CONFIG_CRYPTO_MD5_PPC=m
+CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA1_PPC=m
+CONFIG_CRYPTO_SHA256=y
+CONFIG_CRYPTO_TGR192=m
+CONFIG_CRYPTO_WP512=m
+CONFIG_CRYPTO_ANUBIS=m
+CONFIG_CRYPTO_BLOWFISH=m
+CONFIG_CRYPTO_CAST6=m
+CONFIG_CRYPTO_KHAZAD=m
+CONFIG_CRYPTO_SALSA20=m
+CONFIG_CRYPTO_SERPENT=m
+CONFIG_CRYPTO_TEA=m
+CONFIG_CRYPTO_TWOFISH=m
+CONFIG_CRYPTO_LZO=m
+CONFIG_CRYPTO_DEV_NX=y
+CONFIG_CRYPTO_DEV_NX_ENCRYPT=m
+CONFIG_CRYPTO_DEV_VMX=y
+CONFIG_PRINTK_TIME=y
+CONFIG_PRINTK_CALLER=y
+CONFIG_MAGIC_SYSRQ=y
+CONFIG_DEBUG_KERNEL=y
+CONFIG_DEBUG_STACK_USAGE=y
+CONFIG_DEBUG_STACKOVERFLOW=y
+CONFIG_SOFTLOCKUP_DETECTOR=y
+CONFIG_HARDLOCKUP_DETECTOR=y
+CONFIG_DEBUG_MUTEXES=y
+CONFIG_FUNCTION_TRACER=y
+CONFIG_FTRACE_SYSCALLS=y
+CONFIG_SCHED_TRACER=y
+CONFIG_STACK_TRACER=y
+CONFIG_BLK_DEV_IO_TRACE=y
+CONFIG_CODE_PATCHING_SELFTEST=y
+CONFIG_FTR_FIXUP_SELFTEST=n
+CONFIG_MSI_BITMAP_SELFTEST=y
+CONFIG_XMON=y
+CONFIG_BOOTX_TEXT=y
+CONFIG_LTO=y
+CONFIG_LTO_CLANG_THIN=y
+CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT=n
+CONFIG_USERFAULTFD=y
-- 
2.30.2



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