# git rev-parse -q --verify 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85^{commit} # git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/linus master warning: The last gc run reported the following. Please correct the root cause and remove .git/gc.log. Automatic cleanup will not be performed until the file is removed. warning: There are too many unreachable loose objects; run 'git prune' to remove them. # git rev-parse -q --verify 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85^{commit} 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85 # git checkout -q -f -B kisskb 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85 # git clean -qxdf # < git log -1 # commit 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85 # Author: Linus Torvalds # Date: Wed Mar 10 10:18:04 2021 -0800 # # Revert "mm, slub: consider rest of partial list if acquire_slab() fails" # # This reverts commit 8ff60eb052eeba95cfb3efe16b08c9199f8121cf. # # The kernel test robot reports a huge performance regression due to the # commit, and the reason seems fairly straightforward: when there is # contention on the page list (which is what causes acquire_slab() to # fail), we do _not_ want to just loop and try again, because that will # transfer the contention to the 'n->list_lock' spinlock we hold, and # just make things even worse. # # This is admittedly likely a problem only on big machines - the kernel # test robot report comes from a 96-thread dual socket Intel Xeon Gold # 6252 setup, but the regression there really is quite noticeable: # # -47.9% regression of stress-ng.rawpkt.ops_per_sec # # and the commit that was marked as being fixed (7ced37197196: "slub: # Acquire_slab() avoid loop") actually did the loop exit early very # intentionally (the hint being that "avoid loop" part of that commit # message), exactly to avoid this issue. # # The correct thing to do may be to pick some kind of reasonable middle # ground: instead of breaking out of the loop on the very first sign of # contention, or trying over and over and over again, the right thing may # be to re-try _once_, and then give up on the second failure (or pick # your favorite value for "once"..). # # Reported-by: kernel test robot # Link: https://lore.kernel.org/lkml/20210301080404.GF12822@xsang-OptiPlex-9020/ # Cc: Jann Horn # Cc: David Rientjes # Cc: Joonsoo Kim # Acked-by: Christoph Lameter # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version # < git log --format=%s --max-count=1 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85 # < make -s -j 120 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- randconfig KCONFIG_SEED=0x8294DB08 # Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y # < make -s -j 120 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- help # make -s -j 120 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- olddefconfig .config:6488:warning: override: reassigning to symbol PREVENT_FIRMWARE_BUILD # make -s -j 120 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:27, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/structleak_plugin.c:32: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:102:21: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\ ^ /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:170:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:44, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/structleak_plugin.c:32: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/defaults.h:126:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:27, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/sancov_plugin.c:22: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:102:21: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\ ^ /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:170:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:44, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/sancov_plugin.c:22: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/defaults.h:126:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:27, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/stackleak_plugin.c:30: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:102:21: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\ ^ /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/config/elfos.h:170:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/tm.h:44, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/gcc-plugin.h:31, from /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/plugin.h:23, from /kisskb/src/scripts/gcc-plugins/gcc-common.h:9, from /kisskb/src/scripts/gcc-plugins/stackleak_plugin.c:30: /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/../lib/gcc/aarch64-buildroot-linux-gnu/5.4.0/plugin/include/defaults.h:126:24: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ cc1plus: warning: unrecognized command line option '-Wno-format-diag' cc1plus: warning: unrecognized command line option '-Wno-format-diag' cc1plus: warning: unrecognized command line option '-Wno-format-diag' Completed OK # rm -rf /kisskb/build/linus-rand_arm64-randconfig_arm64-gcc5.4 # Build took: 0:02:12.428505