# git rev-parse -q --verify 86de312343c4b56d699f8ed98aac8bdab1e94225^{commit} 86de312343c4b56d699f8ed98aac8bdab1e94225 already have revision, skipping fetch # git checkout -q -f -B kisskb 86de312343c4b56d699f8ed98aac8bdab1e94225 # git clean -qxdf # < git log -1 # commit 86de312343c4b56d699f8ed98aac8bdab1e94225 # Author: Nicholas Piggin # Date: Mon Jun 10 13:08:18 2019 +1000 # # powerpc/64s/radix: Enable HAVE_ARCH_HUGE_VMAP # # This sets the HAVE_ARCH_HUGE_VMAP option, and defines the required # page table functions. # # This enables huge (2MB and 1GB) ioremap mappings. I don't have a # benchmark for this change, but huge vmap will be used by a later core # kernel change to enable huge vmalloc memory mappings. This improves # cached `git diff` performance by about 5% on a 2-node POWER9 with 32MB # size dentry cache hash. # # Profiling git diff dTLB misses with a vanilla kernel: # # 81.75% git [kernel.vmlinux] [k] __d_lookup_rcu # 7.21% git [kernel.vmlinux] [k] strncpy_from_user # 1.77% git [kernel.vmlinux] [k] find_get_entry # 1.59% git [kernel.vmlinux] [k] kmem_cache_free # # 40,168 dTLB-miss # 0.100342754 seconds time elapsed # # With powerpc huge vmalloc: # # 2,987 dTLB-miss # 0.095933138 seconds time elapsed # # Signed-off-by: Nicholas Piggin # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-ld --version # < git log --format=%s --max-count=1 86de312343c4b56d699f8ed98aac8bdab1e94225 # < make -s -j 120 ARCH=arm O=/kisskb/build/powerpc-next_versatile_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- versatile_defconfig # make -s -j 120 ARCH=arm O=/kisskb/build/powerpc-next_versatile_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:331:21: note: 'pdeo' was declared here /kisskb/src/net/ipv4/ip_output.c: In function '__ip_append_data': /kisskb/src/include/linux/skbuff.h:1406:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv4/ip_output.c:881:14: note: 'extra_uref' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2589:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1850:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv4/fib_semantics.c: In function 'fib_create_info': /kisskb/src/net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv4/fib_semantics.c:971:6: note: 'err' was declared here Completed OK # rm -rf /kisskb/build/powerpc-next_versatile_defconfig_arm # Build took: 0:00:23.322715