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alistair23-linux/arch/sparc/include/asm/futex.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 08:07:57 -06:00
/* SPDX-License-Identifier: GPL-2.0 */
sparc: join the remaining header files With this commit all sparc64 header files are moved to asm-sparc. The remaining files (71 files) were too different to be trivially merged so divide them up in a _32.h and a _64.h file which are both included from the file with no bit size. The following script were used: cd include FILES=`wc -l asm-sparc64/*h | grep -v '^ 1' | cut -b 20-` for FILE in ${FILES}; do echo $FILE: BASE=`echo $FILE | cut -d '.' -f 1` FN32=${BASE}_32.h FN64=${BASE}_64.h GUARD=___ASM_SPARC_`echo $BASE | tr '-' '_' | tr [:lower:] [:upper:]`_H git mv asm-sparc/$FILE asm-sparc/$FN32 git mv asm-sparc64/$FILE asm-sparc/$FN64 echo git mv done printf "#ifndef %s\n" $GUARD > asm-sparc/$FILE printf "#define %s\n" $GUARD >> asm-sparc/$FILE printf "#if defined(__sparc__) && defined(__arch64__)\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN64 >> asm-sparc/$FILE printf "#else\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN32 >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE git add asm-sparc/$FILE echo new file done printf "#include <asm-sparc/%s>\n" $FILE > asm-sparc64/$FILE git add asm-sparc64/$FILE echo sparc64 file done done The guard contains three '_' to avoid conflict with existing guards. In additing the two Kbuild files are emptied to avoid breaking headers_* targets. We will reintroduce the exported header files when the necessary kbuild changes are merged. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17 22:55:51 -06:00
#ifndef ___ASM_SPARC_FUTEX_H
#define ___ASM_SPARC_FUTEX_H
#if defined(__sparc__) && defined(__arch64__)
#include <asm/futex_64.h>
sparc: join the remaining header files With this commit all sparc64 header files are moved to asm-sparc. The remaining files (71 files) were too different to be trivially merged so divide them up in a _32.h and a _64.h file which are both included from the file with no bit size. The following script were used: cd include FILES=`wc -l asm-sparc64/*h | grep -v '^ 1' | cut -b 20-` for FILE in ${FILES}; do echo $FILE: BASE=`echo $FILE | cut -d '.' -f 1` FN32=${BASE}_32.h FN64=${BASE}_64.h GUARD=___ASM_SPARC_`echo $BASE | tr '-' '_' | tr [:lower:] [:upper:]`_H git mv asm-sparc/$FILE asm-sparc/$FN32 git mv asm-sparc64/$FILE asm-sparc/$FN64 echo git mv done printf "#ifndef %s\n" $GUARD > asm-sparc/$FILE printf "#define %s\n" $GUARD >> asm-sparc/$FILE printf "#if defined(__sparc__) && defined(__arch64__)\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN64 >> asm-sparc/$FILE printf "#else\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN32 >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE git add asm-sparc/$FILE echo new file done printf "#include <asm-sparc/%s>\n" $FILE > asm-sparc64/$FILE git add asm-sparc64/$FILE echo sparc64 file done done The guard contains three '_' to avoid conflict with existing guards. In additing the two Kbuild files are emptied to avoid breaking headers_* targets. We will reintroduce the exported header files when the necessary kbuild changes are merged. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17 22:55:51 -06:00
#else
#include <asm/futex_32.h>
sparc: join the remaining header files With this commit all sparc64 header files are moved to asm-sparc. The remaining files (71 files) were too different to be trivially merged so divide them up in a _32.h and a _64.h file which are both included from the file with no bit size. The following script were used: cd include FILES=`wc -l asm-sparc64/*h | grep -v '^ 1' | cut -b 20-` for FILE in ${FILES}; do echo $FILE: BASE=`echo $FILE | cut -d '.' -f 1` FN32=${BASE}_32.h FN64=${BASE}_64.h GUARD=___ASM_SPARC_`echo $BASE | tr '-' '_' | tr [:lower:] [:upper:]`_H git mv asm-sparc/$FILE asm-sparc/$FN32 git mv asm-sparc64/$FILE asm-sparc/$FN64 echo git mv done printf "#ifndef %s\n" $GUARD > asm-sparc/$FILE printf "#define %s\n" $GUARD >> asm-sparc/$FILE printf "#if defined(__sparc__) && defined(__arch64__)\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN64 >> asm-sparc/$FILE printf "#else\n" >> asm-sparc/$FILE printf "#include <asm-sparc/%s>\n" $FN32 >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE printf "#endif\n" >> asm-sparc/$FILE git add asm-sparc/$FILE echo new file done printf "#include <asm-sparc/%s>\n" $FILE > asm-sparc64/$FILE git add asm-sparc64/$FILE echo sparc64 file done done The guard contains three '_' to avoid conflict with existing guards. In additing the two Kbuild files are emptied to avoid breaking headers_* targets. We will reintroduce the exported header files when the necessary kbuild changes are merged. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17 22:55:51 -06:00
#endif
[PATCH] FUTEX_WAKE_OP: pthread_cond_signal() speedup ATM pthread_cond_signal is unnecessarily slow, because it wakes one waiter (which at least on UP usually means an immediate context switch to one of the waiter threads). This waiter wakes up and after a few instructions it attempts to acquire the cv internal lock, but that lock is still held by the thread calling pthread_cond_signal. So it goes to sleep and eventually the signalling thread is scheduled in, unlocks the internal lock and wakes the waiter again. Now, before 2003-09-21 NPTL was using FUTEX_REQUEUE in pthread_cond_signal to avoid this performance issue, but it was removed when locks were redesigned to the 3 state scheme (unlocked, locked uncontended, locked contended). Following scenario shows why simply using FUTEX_REQUEUE in pthread_cond_signal together with using lll_mutex_unlock_force in place of lll_mutex_unlock is not enough and probably why it has been disabled at that time: The number is value in cv->__data.__lock. thr1 thr2 thr3 0 pthread_cond_wait 1 lll_mutex_lock (cv->__data.__lock) 0 lll_mutex_unlock (cv->__data.__lock) 0 lll_futex_wait (&cv->__data.__futex, futexval) 0 pthread_cond_signal 1 lll_mutex_lock (cv->__data.__lock) 1 pthread_cond_signal 2 lll_mutex_lock (cv->__data.__lock) 2 lll_futex_wait (&cv->__data.__lock, 2) 2 lll_futex_requeue (&cv->__data.__futex, 0, 1, &cv->__data.__lock) # FUTEX_REQUEUE, not FUTEX_CMP_REQUEUE 2 lll_mutex_unlock_force (cv->__data.__lock) 0 cv->__data.__lock = 0 0 lll_futex_wake (&cv->__data.__lock, 1) 1 lll_mutex_lock (cv->__data.__lock) 0 lll_mutex_unlock (cv->__data.__lock) # Here, lll_mutex_unlock doesn't know there are threads waiting # on the internal cv's lock Now, I believe it is possible to use FUTEX_REQUEUE in pthread_cond_signal, but it will cost us not one, but 2 extra syscalls and, what's worse, one of these extra syscalls will be done for every single waiting loop in pthread_cond_*wait. We would need to use lll_mutex_unlock_force in pthread_cond_signal after requeue and lll_mutex_cond_lock in pthread_cond_*wait after lll_futex_wait. Another alternative is to do the unlocking pthread_cond_signal needs to do (the lock can't be unlocked before lll_futex_wake, as that is racy) in the kernel. I have implemented both variants, futex-requeue-glibc.patch is the first one and futex-wake_op{,-glibc}.patch is the unlocking inside of the kernel. The kernel interface allows userland to specify how exactly an unlocking operation should look like (some atomic arithmetic operation with optional constant argument and comparison of the previous futex value with another constant). It has been implemented just for ppc*, x86_64 and i?86, for other architectures I'm including just a stub header which can be used as a starting point by maintainers to write support for their arches and ATM will just return -ENOSYS for FUTEX_WAKE_OP. The requeue patch has been (lightly) tested just on x86_64, the wake_op patch on ppc64 kernel running 32-bit and 64-bit NPTL and x86_64 kernel running 32-bit and 64-bit NPTL. With the following benchmark on UP x86-64 I get: for i in nptl-orig nptl-requeue nptl-wake_op; do echo time elf/ld.so --library-path .:$i /tmp/bench; \ for j in 1 2; do echo ( time elf/ld.so --library-path .:$i /tmp/bench ) 2>&1; done; done time elf/ld.so --library-path .:nptl-orig /tmp/bench real 0m0.655s user 0m0.253s sys 0m0.403s real 0m0.657s user 0m0.269s sys 0m0.388s time elf/ld.so --library-path .:nptl-requeue /tmp/bench real 0m0.496s user 0m0.225s sys 0m0.271s real 0m0.531s user 0m0.242s sys 0m0.288s time elf/ld.so --library-path .:nptl-wake_op /tmp/bench real 0m0.380s user 0m0.176s sys 0m0.204s real 0m0.382s user 0m0.175s sys 0m0.207s The benchmark is at: http://sourceware.org/ml/libc-alpha/2005-03/txt00001.txt Older futex-requeue-glibc.patch version is at: http://sourceware.org/ml/libc-alpha/2005-03/txt00002.txt Older futex-wake_op-glibc.patch version is at: http://sourceware.org/ml/libc-alpha/2005-03/txt00003.txt Will post a new version (just x86-64 fixes so that the patch applies against pthread_cond_signal.S) to libc-hacker ml soon. Attached is the kernel FUTEX_WAKE_OP patch as well as a simple-minded testcase that will not test the atomicity of the operation, but at least check if the threads that should have been woken up are woken up and whether the arithmetic operation in the kernel gave the expected results. Acked-by: Ingo Molnar <mingo@redhat.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Jamie Lokier <jamie@shareable.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 16:16:25 -06:00
#endif