linux/arch/alpha/include/uapi, branch v5.9

mm: introduce MADV_PAGEOUT

2019-09-26T00:51:41Z

When a process expects no accesses to a certain memory range for a long time, it could hint kernel that the pages can be reclaimed instantly but data should be preserved for future use. This could reduce workingset eviction so it ends up increasing performance. This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall. MADV_PAGEOUT can be used by a process to mark a memory range as not expected to be used for a long time so that kernel reclaims *any LRU* pages instantly. The hint can help kernel in deciding which pages to evict proactively. A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit intentionally because it's automatically bounded by PMD size. If PMD size(e.g., 256) makes some trouble, we could fix it later by limit it to SWAP_CLUSTER_MAX[1]. - man-page material MADV_PAGEOUT (since Linux x.x) Do not expect access in the near future so pages in the specified regions could be reclaimed instantly regardless of memory pressure. Thus, access in the range after successful operation could cause major page fault but never lose the up-to-date contents unlike MADV_DONTNEED. Pages belonging to a shared mapping are only processed if a write access is allowed for the calling process. MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP pages. [1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/ [minchan@kernel.org: clear PG_active on MADV_PAGEOUT] Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com [akpm@linux-foundation.org: resolve conflicts with hmm.git] Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.org Signed-off-by: Minchan Kim Reported-by: kbuild test robot Acked-by: Michal Hocko Cc: James E.J. Bottomley Cc: Richard Henderson Cc: Ralf Baechle Cc: Chris Zankel Cc: Daniel Colascione Cc: Dave Hansen Cc: Hillf Danton Cc: Joel Fernandes (Google) Cc: Johannes Weiner Cc: Kirill A. Shutemov Cc: Oleksandr Natalenko Cc: Shakeel Butt Cc: Sonny Rao Cc: Suren Baghdasaryan Cc: Tim Murray Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce MADV_COLD

2019-09-26T00:51:41Z

Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7. - Background The Android terminology used for forking a new process and starting an app from scratch is a cold start, while resuming an existing app is a hot start. While we continually try to improve the performance of cold starts, hot starts will always be significantly less power hungry as well as faster so we are trying to make hot start more likely than cold start. To increase hot start, Android userspace manages the order that apps should be killed in a process called ActivityManagerService. ActivityManagerService tracks every Android app or service that the user could be interacting with at any time and translates that into a ranked list for lmkd(low memory killer daemon). They are likely to be killed by lmkd if the system has to reclaim memory. In that sense they are similar to entries in any other cache. Those apps are kept alive for opportunistic performance improvements but those performance improvements will vary based on the memory requirements of individual workloads. - Problem Naturally, cached apps were dominant consumers of memory on the system. However, they were not significant consumers of swap even though they are good candidate for swap. Under investigation, swapping out only begins once the low zone watermark is hit and kswapd wakes up, but the overall allocation rate in the system might trip lmkd thresholds and cause a cached process to be killed(we measured performance swapping out vs. zapping the memory by killing a process. Unsurprisingly, zapping is 10x times faster even though we use zram which is much faster than real storage) so kill from lmkd will often satisfy the high zone watermark, resulting in very few pages actually being moved to swap. - Approach The approach we chose was to use a new interface to allow userspace to proactively reclaim entire processes by leveraging platform information. This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages that are known to be cold from userspace and to avoid races with lmkd by reclaiming apps as soon as they entered the cached state. Additionally, it could provide many chances for platform to use much information to optimize memory efficiency. To achieve the goal, the patchset introduce two new options for madvise. One is MADV_COLD which will deactivate activated pages and the other is MADV_PAGEOUT which will reclaim private pages instantly. These new options complement MADV_DONTNEED and MADV_FREE by adding non-destructive ways to gain some free memory space. MADV_PAGEOUT is similar to MADV_DONTNEED in a way that it hints the kernel that memory region is not currently needed and should be reclaimed immediately; MADV_COLD is similar to MADV_FREE in a way that it hints the kernel that memory region is not currently needed and should be reclaimed when memory pressure rises. This patch (of 5): When a process expects no accesses to a certain memory range, it could give a hint to kernel that the pages can be reclaimed when memory pressure happens but data should be preserved for future use. This could reduce workingset eviction so it ends up increasing performance. This patch introduces the new MADV_COLD hint to madvise(2) syscall. MADV_COLD can be used by a process to mark a memory range as not expected to be used in the near future. The hint can help kernel in deciding which pages to evict early during memory pressure. It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves active file page -> inactive file LRU active anon page -> inacdtive anon LRU Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file LRU's head because MADV_COLD is a little bit different symantic. MADV_FREE means it's okay to discard when the memory pressure because the content of the page is *garbage* so freeing such pages is almost zero overhead since we don't need to swap out and access afterward causes just minor fault. Thus, it would make sense to put those freeable pages in inactive file LRU to compete other used-once pages. It makes sense for implmentaion point of view, too because it's not swapbacked memory any longer until it would be re-dirtied. Even, it could give a bonus to make them be reclaimed on swapless system. However, MADV_COLD doesn't mean garbage so reclaiming them requires swap-out/in in the end so it's bigger cost. Since we have designed VM LRU aging based on cost-model, anonymous cold pages would be better to position inactive anon's LRU list, not file LRU. Furthermore, it would help to avoid unnecessary scanning if system doesn't have a swap device. Let's start simpler way without adding complexity at this moment. However, keep in mind, too that it's a caveat that workloads with a lot of pages cache are likely to ignore MADV_COLD on anonymous memory because we rarely age anonymous LRU lists. * man-page material MADV_COLD (since Linux x.x) Pages in the specified regions will be treated as less-recently-accessed compared to pages in the system with similar access frequencies. In contrast to MADV_FREE, the contents of the region are preserved regardless of subsequent writes to pages. MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP pages. [akpm@linux-foundation.org: resolve conflicts with hmm.git] Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.org Signed-off-by: Minchan Kim Reported-by: kbuild test robot Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: James E.J. Bottomley Cc: Richard Henderson Cc: Ralf Baechle Cc: Chris Zankel Cc: Johannes Weiner Cc: Daniel Colascione Cc: Dave Hansen Cc: Hillf Danton Cc: Joel Fernandes (Google) Cc: Kirill A. Shutemov Cc: Oleksandr Natalenko Cc: Shakeel Butt Cc: Sonny Rao Cc: Suren Baghdasaryan Cc: Tim Murray Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2019-06-20T04:06:27Z

Alexei Starovoitov says: ==================== pull-request: bpf-next 2019-06-19 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) new SO_REUSEPORT_DETACH_BPF setsocktopt, from Martin. 2) BTF based map definition, from Andrii. 3) support bpf_map_lookup_elem for xskmap, from Jonathan. 4) bounded loops and scalar precision logic in the verifier, from Alexei. ==================== Signed-off-by: David S. Miller

bpf: net: Add SO_DETACH_REUSEPORT_BPF

2019-06-14T23:21:19Z

There is SO_ATTACH_REUSEPORT_[CE]BPF but there is no DETACH. This patch adds SO_DETACH_REUSEPORT_BPF sockopt. The same sockopt can be used to undo both SO_ATTACH_REUSEPORT_[CE]BPF. reseport_detach_prog() is added and it is mostly a mirror of the existing reuseport_attach_prog(). The differences are, it does not call reuseport_alloc() and returns -ENOENT when there is no old prog. Cc: Craig Gallek Signed-off-by: Martin KaFai Lau Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

treewide: Add SPDX license identifier - Kbuild

2019-05-30T18:32:33Z

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0 Reported-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman Reviewed-by: Kate Stewart Signed-off-by: Greg Kroah-Hartman

net: socket: implement 64-bit timestamps

2019-04-19T21:07:40Z

The 'timeval' and 'timespec' data structures used for socket timestamps are going to be redefined in user space based on 64-bit time_t in future versions of the C library to deal with the y2038 overflow problem, which breaks the ABI definition. Unlike many modern ioctl commands, SIOCGSTAMP and SIOCGSTAMPNS do not use the _IOR() macro to encode the size of the transferred data, so it remains ambiguous whether the application uses the old or new layout. The best workaround I could find is rather ugly: we redefine the command code based on the size of the respective data structure with a ternary operator. This lets it get evaluated as late as possible, hopefully after that structure is visible to the caller. We cannot use an #ifdef here, because inux/sockios.h might have been included before any libc header that could determine the size of time_t. The ioctl implementation now interprets the new command codes as always referring to the 64-bit structure on all architectures, while the old architecture specific command code still refers to the old architecture specific layout. The new command number is only used when they are actually different. Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller

KVM: export and iif KVM is supported

2019-03-28T16:27:42Z

I do not see any consistency about headers_install of and . According to my analysis of Linux 5.1-rc1, there are 3 groups: [1] Both and are exported alpha, arm, hexagon, mips, powerpc, s390, sparc, x86 [2] is exported, but is not arc, arm64, c6x, h8300, ia64, m68k, microblaze, nios2, openrisc, parisc, sh, unicore32, xtensa [3] Neither nor is exported csky, nds32, riscv This does not match to the actual KVM support. At least, [2] is half-baked. Nor do arch maintainers look like they care about this. For example, commit 0add53713b1c ("microblaze: Add missing kvm_para.h to Kbuild") exported to user-space in order to fix an in-kernel build error. We have two ways to make this consistent: [A] export both and for all architectures, irrespective of the KVM support [B] Match the header export of and to the KVM support My first attempt was [A] because the code looks cleaner, but Paolo suggested [B]. So, this commit goes with [B]. For most architectures, was moved to the kernel-space. I changed include/uapi/linux/Kbuild so that it checks generated asm/kvm_para.h as well as check-in ones. After this commit, there will be two groups: [1] Both and are exported arm, arm64, mips, powerpc, s390, x86 [2] Neither nor is exported alpha, arc, c6x, csky, h8300, hexagon, ia64, m68k, microblaze, nds32, nios2, openrisc, parisc, riscv, sh, sparc, unicore32, xtensa Signed-off-by: Masahiro Yamada Acked-by: Cornelia Huck Signed-off-by: Paolo Bonzini

Merge tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-03-17T20:25:26Z

Pull more Kbuild updates from Masahiro Yamada: - add more Build-Depends to Debian source package - prefix header search paths with $(srctree)/ - make modpost show verbose section mismatch warnings - avoid hard-coded CROSS_COMPILE for h8300 - fix regression for Debian make-kpkg command - add semantic patch to detect missing put_device() - fix some warnings of 'make deb-pkg' - optimize NOSTDINC_FLAGS evaluation - add warnings about redundant generic-y - clean up Makefiles and scripts * tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove stale lxdialog/.gitignore kbuild: force all architectures except um to include mandatory-y kbuild: warn redundant generic-y Revert "modsign: Abort modules_install when signing fails" kbuild: Make NOSTDINC_FLAGS a simply expanded variable kbuild: deb-pkg: avoid implicit effects coccinelle: semantic code search for missing put_device() kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb kbuild: deb-pkg: add CONFIG_ prefix to kernel config options kbuild: add workaround for Debian make-kpkg kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG} unicore32: simplify linker script generation for decompressor h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux- kbuild: move archive command to scripts/Makefile.lib modpost: always show verbose warning for section mismatch ia64: prefix header search path with $(srctree)/ libfdt: prefix header search paths with $(srctree)/ deb-pkg: generate correct build dependencies

kbuild: force all architectures except um to include mandatory-y

2019-03-17T03:56:32Z

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-03-14T16:28:12Z

Pull networking fixes from David Miller: "More fixes in the queue: 1) Netfilter nat can erroneously register the device notifier twice, fix from Florian Westphal. 2) Use after free in nf_tables, from Pablo Neira Ayuso. 3) Parallel update of steering rule fix in mlx5 river, from Eli Britstein. 4) RX processing panic in lan743x, fix from Bryan Whitehead. 5) Use before initialization of TCP_SKB_CB, fix from Christoph Paasch. 6) Fix locking in SRIOV mode of mlx4 driver, from Jack Morgenstein. 7) Fix TX stalls in lan743x due to mishandling of interrupt ACKing modes, from Bryan Whitehead. 8) Fix infoleak in l2tp_ip6_recvmsg(), from Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits) pptp: dst_release sk_dst_cache in pptp_sock_destruct MAINTAINERS: GENET & SYSTEMPORT: Add internal Broadcom list l2tp: fix infoleak in l2tp_ip6_recvmsg() net/tls: Inform user space about send buffer availability net_sched: return correct value for *notify* functions lan743x: Fix TX Stall Issue net/mlx4_core: Fix qp mtt size calculation net/mlx4_core: Fix locking in SRIOV mode when switching between events and polling net/mlx4_core: Fix reset flow when in command polling mode mlxsw: minimal: Initialize base_mac mlxsw: core: Prevent duplication during QSFP module initialization net: dwmac-sun8i: fix a missing check of of_get_phy_mode net: sh_eth: fix a missing check of of_get_phy_mode net: 8390: fix potential NULL pointer dereferences net: fujitsu: fix a potential NULL pointer dereference net: qlogic: fix a potential NULL pointer dereference isdn: hfcpci: fix potential NULL pointer dereference Documentation: devicetree: add a new optional property for port mac address net: rocker: fix a potential NULL pointer dereference net: qlge: fix a potential NULL pointer dereference ...