- 22 Feb, 2024 40 commits
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Nathan Chancellor authored
The minimum supported version of LLVM for building the kernel has been bumped to 13.0.1. Update the __diag_clang() macros for this bump. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-11-f5ff9bda41c5@kernel.orgSigned-off-by:
Nathan Chancellor <nathan@kernel.org> Reviewed-by:
Kees Cook <keescook@chromium.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Conor Dooley <conor@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, this condition can be changed to just CONFIG_CC_IS_CLANG, as the build will fail during the configuration stage for older LLVM versions. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-10-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, this condition is always true, as the build will fail during the configuration stage for older LLVM versions. Remove it. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-9-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, this condition is always true, as the build will fail during the configuration stage for older LLVM versions. Remove it. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-8-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, the condition for using _mcount as MCOUNT_NAME is always true, as the build will fail during the configuration stage for older LLVM versions. Replace MCOUNT_NAME with _mcount directly. This effectively reverts commit 7ce04771 ("riscv: Workaround mcount name prior to clang-13"). Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-7-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
This reverts commit 6fcb5741 ("powerpc: Kconfig: disable CONFIG_COMPAT for clang < 12"). Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, this condition is always true, as the build will fail during the configuration stage for older LLVM versions. Remove it. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-6-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, several conditions become tautologies, as they will always be true because the build will fail during the configuration stage for older LLVM versions. Drop them, as they are unnecessary. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-5-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, the conditional expression added to get_current() by commit c1e42efa ("ARM: 9151/1: Thumb2: avoid __builtin_thread_pointer() on Clang") is always true, as the build will fail during the configuration stage for older LLVM versions. Remove it, effectively reverting the aforementioned change. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-4-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, the inner ifeq statement is always false, as the build will fail during the configuration stage for older LLVM versions. This effectively reverts part of commit b33fff07 ("x86, build: allow LTO to be selected") and its follow up fix, commit 2398ce80 ("x86, lto: Pass -stack-alignment only on LLD < 13.0.0"). Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-3-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, the inner ifeq statement is always false, as the build will fail during the configuration stage for older LLVM versions. This effectively reverts commit 24845dcb ("Makefile: LTO: have linker check -Wframe-larger-than") and its follow up fix, commit 0236526d ("Makefile: lto: Pass -warn-stack-size only on LLD < 13.0.0"). Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-2-f5ff9bda41c5@kernel.orgSigned-off-by:
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Nathan Chancellor authored
Patch series "Bump the minimum supported version of LLVM to 13.0.1". This series bumps the minimum supported version of LLVM for building the kernel to 13.0.1. The first patch does the bump and all subsequent patches clean up all the various workarounds and checks for earlier versions. Quoting the first patch's commit message for those that were only on CC for the clean ups: When __builtin_mul_overflow() has arguments that differ in terms of signedness and width, LLVM may generate a libcall to __muloti4 because it performs the checks in terms of 65-bit multiplication. This issue becomes harder to hit (but still possible) after LLVM 12.0.0, which includes a special case for matching widths but different signs. To gain access to this special case, which the kernel can take advantage of when calls to __muloti4 appear, bump the minimum supported version of LLVM for building the kernel to 13.0.1. 13.0.1 was chosen because there is minimal impact to distribution support while allowing a few more workarounds to be dropped in the kernel source than if 12.0.0 were chosen. Looking at container images of up to date distribution versions: archlinux:latest clang version 16.0.6 debian:oldoldstable-slim clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final) debian:oldstable-slim Debian clang version 11.0.1-2 debian:stable-slim Debian clang version 14.0.6 debian:testing-slim Debian clang version 16.0.6 (19) debian:unstable-slim Debian clang version 16.0.6 (19) fedora:38 clang version 16.0.6 (Fedora 16.0.6-3.fc38) fedora:latest clang version 17.0.6 (Fedora 17.0.6-1.fc39) fedora:rawhide clang version 17.0.6 (Fedora 17.0.6-1.fc40) opensuse/leap:latest clang version 15.0.7 opensuse/tumbleweed:latest clang version 17.0.6 ubuntu:focal clang version 10.0.0-4ubuntu1 ubuntu:latest Ubuntu clang version 14.0.0-1ubuntu1.1 ubuntu:rolling Ubuntu clang version 16.0.6 (15) ubuntu:devel Ubuntu clang version 17.0.6 (3) The only distribution that gets left behind is Debian Bullseye, as the default version is 11.0.1; other distributions either have a newer version than 13.0.1 or one older than the current minimum of 11.0.0. Debian has easy access to more recent LLVM versions through apt.llvm.org, so this is not as much of a concern. There are also the kernel.org LLVM toolchains, which should work with distributions with glibc 2.28 and newer. Another benefit of slimming up the number of supported versions of LLVM for building the kernel is reducing the build capacity needed to support a matrix that builds with each supported version, which allows a matrix to reallocate the freed up build capacity towards something else, such as more configuration combinations. This passes my build matrix with all supported versions. This is based on Andrew's mm-nonmm-unstable to avoid trivial conflicts with my series to update the LLVM links across the repository [1] but I can easily rebase it to linux-kbuild if Masahiro would rather these patches go through there (and defer the conflict resolution to the merge window). [1]: https://lore.kernel.org/20240109-update-llvm-links-v1-0-eb09b59db071@kernel.org/ This patch (of 11): When __builtin_mul_overflow() has arguments that differ in terms of signedness and width, LLVM may generate a libcall to __muloti4 because it performs the checks in terms of 65-bit multiplication. This issue becomes harder to hit (but still possible) after LLVM 12.0.0, which includes a special case for matching widths but different signs. To gain access to this special case, which the kernel can take advantage of when calls to __muloti4 appear, bump the minimum supported version of LLVM for building the kernel to 13.0.1. 13.0.1 was chosen because there is minimal impact to distribution support while allowing a few more workarounds to be dropped in the kernel source than if 12.0.0 were chosen. Looking at container images of up to date distribution versions: archlinux:latest clang version 16.0.6 debian:oldoldstable-slim clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final) debian:oldstable-slim Debian clang version 11.0.1-2 debian:stable-slim Debian clang version 14.0.6 debian:testing-slim Debian clang version 16.0.6 (19) debian:unstable-slim Debian clang version 16.0.6 (19) fedora:38 clang version 16.0.6 (Fedora 16.0.6-3.fc38) fedora:latest clang version 17.0.6 (Fedora 17.0.6-1.fc39) fedora:rawhide clang version 17.0.6 (Fedora 17.0.6-1.fc40) opensuse/leap:latest clang version 15.0.7 opensuse/tumbleweed:latest clang version 17.0.6 ubuntu:focal clang version 10.0.0-4ubuntu1 ubuntu:latest Ubuntu clang version 14.0.0-1ubuntu1.1 ubuntu:rolling Ubuntu clang version 16.0.6 (15) ubuntu:devel Ubuntu clang version 17.0.6 (3) The only distribution that gets left behind is Debian Bullseye, as the default version is 11.0.1; other distributions either have a newer version than 13.0.1 or one older than the current minimum of 11.0.0. Debian has easy access to more recent LLVM versions through apt.llvm.org, so this is not as much of a concern. There are also the kernel.org LLVM toolchains, which should work with distributions with glibc 2.28 and newer. Another benefit of slimming up the number of supported versions of LLVM for building the kernel is reducing the build capacity needed to support a matrix that builds with each supported version, which allows a matrix to reallocate the freed up build capacity towards something else, such as more configuration combinations. Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-0-f5ff9bda41c5@kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1975 Link: https://github.com/llvm/llvm-project/issues/38013 Link: https://github.com/llvm/llvm-project/commit/3203143f1356a4e4e3ada231156fc6da6e1a9f9d Link: https://mirrors.edge.kernel.org/pub/tools/llvm/ Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-1-f5ff9bda41c5@kernel.orgSigned-off-by: -
Ryusuke Konishi authored
Convert all remaining usages of kmap_atomic in cpfile to kmap_local. Link: https://lkml.kernel.org/r/20240122140202.6950-16-konishi.ryusuke@gmail.comSigned-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by:
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Ryusuke Konishi authored
All calls to nilfs_cpfile_get_checkpoint() and nilfs_cpfile_put_checkpoint() that call kmap() and kunmap() separately are now gone, so remove these methods. Link: https://lkml.kernel.org/r/20240122140202.6950-15-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Move the code for reading from a checkpoint entry that is performed in nilfs_attach_checkpoint() to the cpfile side, and make the page mapping local and temporary. And use kmap_local instead of kmap to access the checkpoint entry page. In order to load the ifile inode information included in the checkpoint entry within the inode lock section of nilfs_ifile_read(), the newly added checkpoint reading method nilfs_cpfile_read_checkpoint() is called indirectly via nilfs_ifile_read() instead of from nilfs_attach_checkpoint(). Link: https://lkml.kernel.org/r/20240122140202.6950-14-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Move the checkpoint finalization routine to the cpfile side, and make the page mapping local and temporary. And use kmap_local instead of kmap to access the checkpoint entry page when finalizing a checkpoint. In this conversion, some of the information on the checkpoint entry being rewritten is passed through the arguments of the newly added method nilfs_cpfile_finalize_checkpoint(). Link: https://lkml.kernel.org/r/20240122140202.6950-13-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
In order to convert kmap() used in cpfile to kmap_local, first move the checkpoint creation routine, which is one of the places where kmap is used, to the cpfile side and make the page mapping local and temporary. And use kmap_local instead of kmap to access the checkpoint entry page (and header block page) when generating a checkpoint. Link: https://lkml.kernel.org/r/20240122140202.6950-12-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Convert deprecated kmap() and kmap_atomic() to use kmap_local for the ifile metadata file used to manage disk inodes. In some usages, calls to kmap_local and kunmap_local are split into different helpers, but those usages can be safely changed to local thread kmap. Link: https://lkml.kernel.org/r/20240122140202.6950-11-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
It is now clear that nilfs_bmap_write() is only used to finalize logs written to disk. Concurrent bmap modification operations are not performed on bmaps in this context. Additionally, this function does not modify data used in read-only operations such as bmap lookups. Therefore, there is no need to acquire bmap->b_sem in nilfs_bmap_write(), so delete it. Link: https://lkml.kernel.org/r/20240122140202.6950-10-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Before converting the disk inode management metadata file ifile, the call to nilfs_bmap_write(), the i_device_code setting, and the zero-fill code for inodes on the super root block are moved from nilfs_write_inode_common() to its callers. This cleanup simplifies the role and arguments of nilfs_write_inode_common() and collects calls to nilfs_bmap_write() to the log writing code. Also, add and use a new helper nilfs_write_root_mdt_inode() to avoid code duplication in the data export routine nilfs_segctor_fill_in_super_root() to the super root block's buffer. Link: https://lkml.kernel.org/r/20240122140202.6950-9-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Concerning the code of the metadata file DAT for disk address translation, convert all parts that use the deprecated kmap_atomic to use kmap_local. All transformations are directly possible. Link: https://lkml.kernel.org/r/20240122140202.6950-8-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Regarding the allocator code that is commonly used in the ondisk inode metadata file ifile and the disk address translation metadata file DAT, convert the parts that use the deprecated kmap_atomic() and kmap() to use kmap_local. Most can be converted directly, but only nilfs_palloc_prepare_alloc_entry() needs to be rewritten to change mapping sections so that multiple kmap_local/kunmap_local calls are nested and disk I/O can be avoided within the mapping sections. Link: https://lkml.kernel.org/r/20240122140202.6950-7-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Concerning the code of the metadata file sufile for segment management, convert all parts that uses the deprecated kmap_atomic() to use kmap_local. All transformations are directly possible here. Link: https://lkml.kernel.org/r/20240122140202.6950-6-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
In the common code of metadata files, the new block creation routine nilfs_mdt_insert_new_block() still uses the deprecated kmap_atomic(), so convert it to use kmap_local. Link: https://lkml.kernel.org/r/20240122140202.6950-5-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
The routine nilfs_copy_buffer() that copies a block buffer still uses the deprecated kmap_atomic(), so convert it to use kmap_local. Link: https://lkml.kernel.org/r/20240122140202.6950-4-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
In the segment buffer code used for log writing, a CRC calculation routine uses the deprecated kmap_atomic(), so convert it to use kmap_local. Link: https://lkml.kernel.org/r/20240122140202.6950-3-konishi.ryusuke@gmail.comSigned-off-by:
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Ryusuke Konishi authored
Patch series "nilfs2: eliminate kmap and kmap_atomic calls". This series converts remaining kmap and kmap_atomic calls to use kmap_local, mainly in metadata files, and eliminates calls to these deprecated kmap functions from nilfs2. This series does not include converting metadata files to use folios, but it is a step in that direction. Most conversions are straightforward, but some are not: the checkpoint file, the inode file, and the persistent object allocator. These have been adjusted or rewritten to avoid multiple kmap_local calls or nest them if necessary, and to eliminate long waits like block I/O within the highmem mapping sections. This series has been tested in both 32-bit and 64-bit environments with varying block sizes. This patch (of 15): In the recovery function when mounting, nilfs_recovery_copy_block() uses the deprecated kmap_atomic(), so convert it to use kmap_local. Link: https://lkml.kernel.org/r/20240122140202.6950-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240122140202.6950-2-konishi.ryusuke@gmail.comSigned-off-by:
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Geert Uytterhoeven authored
The help text for the Dhrystone benchmark test lacks a matching closing parenthesis. Link: https://lkml.kernel.org/r/772b43271bcb3dd17a6aae671b2084f08c05b079.1705934853.git.geert+renesas@glider.beSigned-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by:
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Geert Uytterhoeven authored
Use the existing ktime_ms_delta() helper instead of open-coding the same operation. Link: https://lkml.kernel.org/r/bb43c67a7580de6152f5e6eb225071166d33b6e4.1705934853.git.geert+renesas@glider.beSigned-off-by:
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Geert Uytterhoeven authored
Patch series "lib: dhry: miscellaneous cleanups". This patch series contains a few miscellaneous cleanups for the Dhrystone benchmark test. This patch (of 3): The Dhrystone benchmark test does not use mutexes. Link: https://lkml.kernel.org/r/cover.1705934853.git.geert+renesas@glider.be Link: https://lkml.kernel.org/r/cf8fafaedccf96143f1513745c43a457480bfc24.1705934853.git.geert+renesas@glider.beSigned-off-by:
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Oleg Nesterov authored
Turn send_sig_info(SIGSTOP) into send_signal_locked(SIGSTOP) and move it from ptrace_attach() to ptrace_set_stopped(). This looks more logical and avoids lock(siglock) right after unlock(). Link: https://lkml.kernel.org/r/20240122171631.GA29844@redhat.comSigned-off-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Kemeng Shi authored
The single variant of flex_proportions is not used. Simply remove it. Link: https://lkml.kernel.org/r/20240118201321.759174-1-shikemeng@huaweicloud.comSigned-off-by:
Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Kuan-Wei Chiu authored
Instead of popping only the maximum element from the heap during each iteration, we now pop the two largest elements at once. Although this introduces an additional comparison to determine the second largest element, it enables a reduction in the height of the tree by one during the heapify operations starting from root's left/right child. This reduction in tree height by one leads to a decrease of one comparison and one swap. This optimization results in saving approximately 0.5 * n swaps without increasing the number of comparisons. Additionally, the heap size during heapify is now one less than the original size, offering a chance for further reduction in comparisons and swaps. The following experimental data is based on the array generated using get_random_u32(). | N | swaps (old) | swaps (new) | comparisons (old) | comparisons (new) | |-------|-------------|-------------|-------------------|-------------------| | 1000 | 9054 | 8569 | 10328 | 10320 | | 2000 | 20137 | 19182 | 22634 | 22587 | | 3000 | 32062 | 30623 | 35833 | 35752 | | 4000 | 44274 | 42282 | 49332 | 49306 | | 5000 | 57195 | 54676 | 63300 | 63294 | | 6000 | 70205 | 67202 | 77599 | 77557 | | 7000 | 83276 | 79831 | 92113 | 92032 | | 8000 | 96630 | 92678 | 106635 | 106617 | | 9000 | 110349 | 105883 | 121505 | 121404 | | 10000 | 124165 | 119202 | 136628 | 136617 | Link: https://lkml.kernel.org/r/20240113031352.2395118-3-visitorckw@gmail.comSigned-off-by:
Kuan-Wei Chiu <visitorckw@gmail.com> Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Cc: George Spelvin <lkml@sdf.org> Signed-off-by:
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Kuan-Wei Chiu authored
Patch series "lib/sort: Optimize the number of swaps and comparisons". This patch series aims to optimize the heapsort algorithm, specifically targeting a reduction in the number of swaps and comparisons required. This patch (of 2): Currently, when searching for the sift-down path and encountering equal elements, the algorithm chooses the left child. However, considering that the height of the right subtree may be one less than that of the left subtree, selecting the right child in such cases can potentially reduce the number of comparisons and swaps. For instance, when sorting an array of 10,000 identical elements, the current implementation requires 247,209 comparisons. With this patch, the number of comparisons can be reduced to 227,241. Link: https://lkml.kernel.org/r/20240113031352.2395118-1-visitorckw@gmail.com Link: https://lkml.kernel.org/r/20240113031352.2395118-2-visitorckw@gmail.comSigned-off-by:
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Li zeming authored
kbuf is assigned first, so it does not need to initialize the assignment. Link: https://lkml.kernel.org/r/20240115062519.31298-1-zeming@nfschina.comSigned-off-by:
Li zeming <zeming@nfschina.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Alexey Gladkov authored
All parameters of posix messages queues (queues_max/msg_max/msgsize_max) end up being limited by RLIMIT_MSGQUEUE. The code in mqueue_get_inode is where that limiting happens. The RLIMIT_MSGQUEUE is bound to the user namespace and is counted hierarchically. We can allow root in the user namespace to modify the posix messages queues parameters. Link: https://lkml.kernel.org/r/6ad67f23d1459a4f4339f74aa73bac0ecf3995e1.1705333426.git.legion@kernel.orgSigned-off-by:
Alexey Gladkov <legion@kernel.org> Signed-off-by:
Eric W. Biederman <ebiederm@xmission.com> Link: https://lkml.kernel.org/r/7eb21211c8622e91d226e63416b1b93c079f60ee.1663756794.git.legion@kernel.org Cc: Christian Brauner <brauner@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Joel Granados <joel.granados@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Alexey Gladkov authored
After 25b21cb2 ("[PATCH] IPC namespace core") and 4e982311 ("[PATCH] IPC namespace - shm") the shared memory page count stopped being global and started counting per ipc namespace. The documentation and shmget(2) still says that shmall is a global option. shmget(2): SHMALL System-wide limit on the total amount of shared memory, measured in units of the system page size. On Linux, this limit can be read and modified via /proc/sys/kernel/shmall. I think the changes made in 2006 should be documented. Link: https://lkml.kernel.org/r/09e99911071766958af488beb4e8a728a4f12135.1705333426.git.legion@kernel.orgSigned-off-by:
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Alexey Gladkov authored
Patch series "Allow to change ipc/mq sysctls inside ipc namespace", v3. Right now ipc and mq limits count as per ipc namespace, but only real root can change them. By default, the current values of these limits are such that it can only be reduced. Since only root can change the values, it is impossible to reduce these limits in the rootless container. We can allow limit changes within ipc namespace because mq parameters are limited by RLIMIT_MSGQUEUE and ipc parameters are not limited to anything other than cgroups. This patch (of 3): Rootless containers are not allowed to modify kernel IPC parameters. All default limits are set to such high values that in fact there are no limits at all. All limits are not inherited and are initialized to default values when a new ipc_namespace is created. For new ipc_namespace: size_t ipc_ns.shm_ctlmax = SHMMAX; // (ULONG_MAX - (1UL << 24)) size_t ipc_ns.shm_ctlall = SHMALL; // (ULONG_MAX - (1UL << 24)) int ipc_ns.shm_ctlmni = IPCMNI; // (1 << 15) int ipc_ns.shm_rmid_forced = 0; unsigned int ipc_ns.msg_ctlmax = MSGMAX; // 8192 unsigned int ipc_ns.msg_ctlmni = MSGMNI; // 32000 unsigned int ipc_ns.msg_ctlmnb = MSGMNB; // 16384 The shm_tot (total amount of shared pages) has also ceased to be global, it is located in ipc_namespace and is not inherited from anywhere. In such conditions, it cannot be said that these limits limit anything. The real limiter for them is cgroups. If we allow rootless containers to change these parameters, then it can only be reduced. Link: https://lkml.kernel.org/r/cover.1705333426.git.legion@kernel.org Link: https://lkml.kernel.org/r/d2f4603305cbfed58a24755aa61d027314b73a45.1705333426.git.legion@kernel.orgSigned-off-by:
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Kuan-Wei Chiu authored
Optimize the min_heapify() function, resulting in a significant reduction of approximately 50% in the number of comparisons for large random inputs, while maintaining identical results. The current implementation performs two comparisons per level to identify the minimum among three elements. In contrast, the proposed bottom-up variation uses only one comparison per level to assess two children until reaching the leaves. Then, it sifts up until the correct position is determined. Typically, the process of sifting down proceeds to the leaf level, resulting in O(1) secondary comparisons instead of log2(n). This optimization significantly reduces the number of costly indirect function calls and improves overall performance. Link: https://lkml.kernel.org/r/20240110081213.2289636-3-visitorckw@gmail.comSigned-off-by:
Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Kuan-Wei Chiu authored
Patch series "lib min_heap: Min heap optimizations". The purpose of this patch series is to enhance the existing min heap implementation. The optimization focuses on both the heap construction process and the number of comparisons made during the heapify operation. This patch (of 2): Improve the heap construction process by reducing unnecessary heapify operations. Specifically, adjust the starting condition from n / 2 to n / 2 - 1 in the loop that iterates over all non-leaf elements. Link: https://lkml.kernel.org/r/20240110081213.2289636-1-visitorckw@gmail.com Link: https://lkml.kernel.org/r/20240110081213.2289636-2-visitorckw@gmail.comSigned-off-by:
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Baoquan He authored
with GCC 13.2.1 and W=1, there's compiling warning like this: kernel/panic.c: In function `__warn': kernel/panic.c:676:17: warning: function `__warn' might be a candidate for `gnu_printf' format attribute [-Wsuggest-attribute=format] 676 | vprintk(args->fmt, args->args); | ^~~~~~~ The normal __printf(x,y) adding can't fix it. So add workaround which disables -Wsuggest-attribute=format to mute it. Link: https://lkml.kernel.org/r/20240107091641.579849-1-bhe@redhat.comSigned-off-by:Baoquan He <bhe@redhat.com> Signed-off-by:
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