Buildresult: linus/ia64-defconfig/ia64-gcc4.9 built on Nov 27 2020, 05:29

kisskb

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Status:	OK
Date/Time:	Nov 27 2020, 05:29
Duration:	0:02:25.441462
Builder:	ka3
Revision:	mm: memcg: relayout structure mem_cgroup to avoid cache interference (`4df910620bebb5cfe234af16ac8f6474b60215fd)`
Target:	linus/ia64-defconfig/ia64-gcc4.9
Branch:	linus
Compiler:	ia64-gcc4.9 (ia64-linux-gcc (GCC) 4.9.4 / GNU ld (GNU Binutils) 2.29.1.20170915)
Config:	defconfig (download)
Log:	Download original Possible warnings (5) arch/ia64/configs/generic_defconfig:58:warning: override: reassigning to symbol ATA arch/ia64/configs/generic_defconfig:59:warning: override: reassigning to symbol ATA_PIIX <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] arch/ia64/include/uapi/asm/cmpxchg.h:57:2: warning: value computed is not used [-Wunused-value] arch/ia64/include/uapi/asm/cmpxchg.h:57:2: warning: value computed is not used [-Wunused-value] Full Log # git rev-parse -q --verify 4df910620bebb5cfe234af16ac8f6474b60215fd^{commit} 4df910620bebb5cfe234af16ac8f6474b60215fd already have revision, skipping fetch # git checkout -q -f -B kisskb 4df910620bebb5cfe234af16ac8f6474b60215fd # git clean -qxdf # < git log -1 # commit 4df910620bebb5cfe234af16ac8f6474b60215fd # Author: Feng Tang <feng.tang@intel.com> # Date: Wed Nov 25 13:22:21 2020 +0800 # # mm: memcg: relayout structure mem_cgroup to avoid cache interference # # 0day reported one -22.7% regression for will-it-scale page_fault2 # case [1] on a 4 sockets 144 CPU platform, and bisected to it to be # caused by Waiman's optimization (commit bd0b230fe1) of saving one # 'struct page_counter' space for 'struct mem_cgroup'. # # Initially we thought it was due to the cache alignment change introduced # by the patch, but further debug shows that it is due to some hot data # members ('vmstats_local', 'vmstats_percpu', 'vmstats') sit in 2 adjacent # cacheline (2N and 2N+1 cacheline), and when adjacent cache line prefetch # is enabled, it triggers an "extended level" of cache false sharing for # 2 adjacent cache lines. # # So exchange the 2 member blocks, while keeping mostly the original # cache alignment, which can restore and even enhance the performance, # and save 64 bytes of space for 'struct mem_cgroup' (from 2880 to 2816, # with 0day's default RHEL-8.3 kernel config) # # [1]. https://lore.kernel.org/lkml/20201102091543.GM31092@shao2-debian/ # # Fixes: bd0b230fe145 ("mm/memcg: unify swap and memsw page counters") # Reported-by: kernel test robot <rong.a.chen@intel.com> # Signed-off-by: Feng Tang <feng.tang@intel.com> # Acked-by: Waiman Long <longman@redhat.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux-ld --version # < git log --format=%s --max-count=1 4df910620bebb5cfe234af16ac8f6474b60215fd # < make -s -j 80 ARCH=ia64 O=/kisskb/build/linus_ia64-defconfig_ia64-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux- defconfig arch/ia64/configs/generic_defconfig:58:warning: override: reassigning to symbol ATA arch/ia64/configs/generic_defconfig:59:warning: override: reassigning to symbol ATA_PIIX # < make -s -j 80 ARCH=ia64 O=/kisskb/build/linus_ia64-defconfig_ia64-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux- help # make -s -j 80 ARCH=ia64 O=/kisskb/build/linus_ia64-defconfig_ia64-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux- olddefconfig # make -s -j 80 ARCH=ia64 O=/kisskb/build/linus_ia64-defconfig_ia64-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/ia64-linux/bin/ia64-linux- <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] In file included from /kisskb/src/arch/ia64/include/uapi/asm/intrinsics.h:22:0, from /kisskb/src/arch/ia64/include/asm/intrinsics.h:11, from /kisskb/src/arch/ia64/include/asm/timex.h:14, from /kisskb/src/include/linux/timex.h:65, from /kisskb/src/include/linux/time32.h:13, from /kisskb/src/include/linux/time.h:73, from /kisskb/src/fs/nfs/read.c:11: /kisskb/src/fs/nfs/read.c: In function 'nfs_read_completion': /kisskb/src/arch/ia64/include/uapi/asm/cmpxchg.h:57:2: warning: value computed is not used [-Wunused-value] ((__typeof__((ptr))) __xchg((unsigned long) (x), (ptr), sizeof((ptr)))) ^ /kisskb/src/fs/nfs/read.c:196:5: note: in expansion of macro 'xchg' xchg(&nfs_req_openctx(req)->error, error); ^ /kisskb/src/fs/nfs/read.c: In function 'nfs_readpage': /kisskb/src/arch/ia64/include/uapi/asm/cmpxchg.h:57:2: warning: value computed is not used [-Wunused-value] ((__typeof__((ptr))) __xchg((unsigned long) (x), (ptr), sizeof((ptr)))) ^ /kisskb/src/fs/nfs/read.c:355:2: note: in expansion of macro 'xchg' xchg(&ctx->error, 0); ^ No errors detected in 22333 functions. Completed OK # rm -rf /kisskb/build/linus_ia64-defconfig_ia64-gcc4.9 # Build took: 0:02:25.441462

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