Buildresult: linus/44x/currituck_defconfig/powerpc-gcc4.6 built on Jan 24 2019, 08:27

kisskb

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Status:	OK
Date/Time:	Jan 24 2019, 08:27
Duration:	0:00:47.503473
Builder:	ka2
Revision:	Revert "Change mincore() to count "mapped" pages rather than "cached" pages" (`30bac164aca750892b93eef350439a0562a68647)`
Target:	linus/44x/currituck_defconfig/powerpc-gcc4.6
Branch:	linus
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3 / GNU ld (GNU Binutils) 2.22)
Config:	44x/currituck_defconfig (download)
Log:	Download original Possible warnings (15) WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] kernel/rcu/srcutree.c:152:32: warning: 'levelspread[<U5e60>]' may be used uninitialized in this function [-Wuninitialized] include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] kernel/trace/trace_dynevent.c:89:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/base/regmap/regmap.c:2594:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/base/regmap/regmap.c:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] arch/powerpc/boot/dts/currituck.dts:125.28-161.5: Warning (pci_bridge): /plb/pciex@10100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dts:163.28-198.5: Warning (pci_bridge): /plb/pciex@30100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dts:200.28-235.5: Warning (pci_bridge): /plb/pciex@38100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Full Log # git rev-parse -q --verify 30bac164aca750892b93eef350439a0562a68647^{commit} 30bac164aca750892b93eef350439a0562a68647 already have revision, skipping fetch # git checkout -q -f -B kisskb 30bac164aca750892b93eef350439a0562a68647 # git clean -qxdf # < git log -1 # commit 30bac164aca750892b93eef350439a0562a68647 # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Thu Jan 24 09:04:37 2019 +1300 # # Revert "Change mincore() to count "mapped" pages rather than "cached" pages" # # This reverts commit 574823bfab82d9d8fa47f422778043fbb4b4f50e. # # It turns out that my hope that we could just remove the code that # exposes the cache residency status from mincore() was too optimistic. # # There are various random users that want it, and one example would be # the Netflix database cluster maintenance. To quote Josh Snyder: # # "For Netflix, losing accurate information from the mincore syscall # would lengthen database cluster maintenance operations from days to # months. We rely on cross-process mincore to migrate the contents of a # page cache from machine to machine, and across reboots. # # To do this, I wrote and maintain happycache [1], a page cache # dumper/loader tool. It is quite similar in architecture to pgfincore, # except that it is agnostic to workload. The gist of happycache's # operation is "produce a dump of residence status for each page, do # some operation, then reload exactly the same pages which were present # before." happycache is entirely dependent on accurate reporting of the # in-core status of file-backed pages, as accessed by another process. # # We primarily use happycache with Cassandra, which (like Postgres + # pgfincore) relies heavily on OS page cache to reduce disk accesses. # Because our workloads never experience a cold page cache, we are able # to provision hardware for a peak utilization level that is far lower # than the hypothetical "every query is a cache miss" peak. # # A database warmed by happycache can be ready for service in seconds # (bounded only by the performance of the drives and the I/O subsystem), # with no period of in-service degradation. By contrast, putting a # database in service without a page cache entails a potentially # unbounded period of degradation (at Netflix, the time to populate a # single node's cache via natural cache misses varies by workload from # hours to weeks). If a single node upgrade were to take weeks, then # upgrading an entire cluster would take months. Since we want to apply # security upgrades (and other things) on a somewhat tighter schedule, # we would have to develop more complex solutions to provide the same # functionality already provided by mincore. # # At the bottom line, happycache is designed to benignly exploit the # same information leak documented in the paper [2]. I think it makes # perfect sense to remove cross-process mincore functionality from # unprivileged users, but not to remove it entirely" # # We do have an alternate approach that limits the cache residency # reporting only to processes that have write permissions to the file, so # we can fix the original information leak issue that way. It involves # _adding_ code rather than removing it, which is sad, but hey, at least # we haven't found any users that would find the restrictions # unacceptable. # # So revert the optimistic first approach to make room for that alternate # fix instead. # # Reported-by: Josh Snyder <joshs@netflix.com> # Cc: Jiri Kosina <jikos@kernel.org> # Cc: Dominique Martinet <asmadeus@codewreck.org> # Cc: Andy Lutomirski <luto@amacapital.net> # Cc: Dave Chinner <david@fromorbit.com> # Cc: Kevin Easton <kevin@guarana.org> # Cc: Matthew Wilcox <willy@infradead.org> # Cc: Cyril Hrubis <chrubis@suse.cz> # Cc: Vlastimil Babka <vbabka@suse.cz> # Cc: Tejun Heo <tj@kernel.org> # Cc: Kirill A. Shutemov <kirill@shutemov.name> # Cc: Daniel Gruss <daniel@gruss.cc> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 30bac164aca750892b93eef350439a0562a68647 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_44x_currituck_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- 44x/currituck_defconfig WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS Depends on [n]: PCI [=n] && 4xx [=y] Selected by [y]: - CURRITUCK [=y] && PPC_47x [=y] WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS Depends on [n]: PCI [=n] && 4xx [=y] Selected by [y]: - CURRITUCK [=y] && PPC_47x [=y] WARNING: unmet direct dependencies detected for PPC4xx_PCI_EXPRESS Depends on [n]: PCI [=n] && 4xx [=y] Selected by [y]: - CURRITUCK [=y] && PPC_47x [=y] # make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_44x_currituck_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields': /kisskb/src/kernel/rcu/srcutree.c:152:32: warning: 'levelspread[<U5e60>]' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c:100:6: note: 'levelspread[<U5e60>]' was declared here /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:339:21: note: 'pdeo' was declared here /kisskb/src/kernel/trace/trace_dynevent.c: In function 'create_dyn_event': /kisskb/src/kernel/trace/trace_dynevent.c:89:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2594:6: 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:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/arch/powerpc/boot/dts/currituck.dts:125.28-161.5: Warning (pci_bridge): /plb/pciex@10100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/currituck.dts:163.28-198.5: Warning (pci_bridge): /plb/pciex@30100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/currituck.dts:200.28-235.5: Warning (pci_bridge): /plb/pciex@38100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Completed OK # rm -rf /kisskb/build/linus_44x_currituck_defconfig_powerpc-gcc4.6 # Build took: 0:00:47.503473

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