mirror of https://github.com/torvalds/linux.git
005b2a9dc8
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl/YJxsQHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpjpyEACBdW+YjenjTbkUPeEXzQgkBkTZUYw3g007 DPcUT1g8PQZXYXlQvBKCvGhhIr7/KVcjepKoowiNQfBNGcIPJTVopW58nzpqAfTQ goI2WYGn5EKFFKBPvtH04cJD/Wo8muXdxynKtqyZbnGGgZjQxPrE259b8dpHjBSR 6L7HHkk0D1oU/5b6h6Ocpg9mc/0iIUCZylySAYY3eGO0JaVPJaXgZSJZYgHxCHll Lb+/y/fXdtm/0PmQ3ko0ev54g3yEWqZIX0NsZW1asrButIy+KLzQ2Mz1xFLFDMag prtIfwb8tzgc4dFPY090C/azjCh5CPpxqYS6FkRwS0p86n6OhkyXrqfily5Hs4/B NC7CBPBSH/j+NKUK7CYZcpTzTpxPjUr9p0anUdlvMJz8FhTb/3YEEZ1UTeWOeHmk Yo5SxnFghLeZZeZ1ok6rdymnVa7WEX12SCLGQX31BB2mld0tNbKb4b+FsBF6OUMk IUaX6OjwDFVRaysC88BQ4hjcIP1HxsViG4/VZDX15gjAAH2Pvb+7tev+lcDcOhjz TCD4GNFspTFzRhh9nT7oxQ679qCh9G9zHbzuIRewnrS6iqvo5SJQB3dR2yrWZRRH ySkQFiHpYOlnLJYv0jg9COlGwo2FUdcvKhCvkjQKKBz48rzW/IC0LwKdRQWZDFk3 FKGzP/NBig== =cadT -----END PGP SIGNATURE----- Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe: "This sits on top of of the core entry/exit and x86 entry branch from the tip tree, which contains the generic and x86 parts of this work. Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL. With that done, we can get rid of JOBCTL_TASK_WORK from task_work and signal.c, and also remove a deadlock work-around in io_uring around knowing that signal based task_work waking is invoked with the sighand wait queue head lock. The motivation for this work is to decouple signal notify based task_work, of which io_uring is a heavy user of, from sighand. The sighand lock becomes a huge contention point, particularly for threaded workloads where it's shared between threads. Even outside of threaded applications it's slower than it needs to be. Roman Gershman <romger@amazon.com> reported that his networked workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all spent hammering on the sighand lock, showing 57% of the CPU time there [1]. There are further cleanups possible on top of this. One example is TIF_PATCH_PENDING, where a patch already exists to use TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more consolidation, but the work stands on its own as well" [1] https://github.com/axboe/liburing/issues/215 * tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits) io_uring: remove 'twa_signal_ok' deadlock work-around kernel: remove checking for TIF_NOTIFY_SIGNAL signal: kill JOBCTL_TASK_WORK io_uring: JOBCTL_TASK_WORK is no longer used by task_work task_work: remove legacy TWA_SIGNAL path sparc: add support for TIF_NOTIFY_SIGNAL riscv: add support for TIF_NOTIFY_SIGNAL nds32: add support for TIF_NOTIFY_SIGNAL ia64: add support for TIF_NOTIFY_SIGNAL h8300: add support for TIF_NOTIFY_SIGNAL c6x: add support for TIF_NOTIFY_SIGNAL alpha: add support for TIF_NOTIFY_SIGNAL xtensa: add support for TIF_NOTIFY_SIGNAL arm: add support for TIF_NOTIFY_SIGNAL microblaze: add support for TIF_NOTIFY_SIGNAL hexagon: add support for TIF_NOTIFY_SIGNAL csky: add support for TIF_NOTIFY_SIGNAL openrisc: add support for TIF_NOTIFY_SIGNAL sh: add support for TIF_NOTIFY_SIGNAL um: add support for TIF_NOTIFY_SIGNAL ... |
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| .. | ||
| Kbuild | ||
| adc.h | ||
| addrspace.h | ||
| alignment.h | ||
| asm-offsets.h | ||
| atomic-grb.h | ||
| atomic-irq.h | ||
| atomic-llsc.h | ||
| atomic.h | ||
| barrier.h | ||
| bitops-cas.h | ||
| bitops-grb.h | ||
| bitops-llsc.h | ||
| bitops-op32.h | ||
| bitops.h | ||
| bl_bit.h | ||
| bl_bit_32.h | ||
| bug.h | ||
| bugs.h | ||
| cache.h | ||
| cache_insns.h | ||
| cache_insns_32.h | ||
| cacheflush.h | ||
| checksum.h | ||
| checksum_32.h | ||
| clock.h | ||
| cmpxchg-cas.h | ||
| cmpxchg-grb.h | ||
| cmpxchg-irq.h | ||
| cmpxchg-llsc.h | ||
| cmpxchg-xchg.h | ||
| cmpxchg.h | ||
| device.h | ||
| dma-register.h | ||
| dma.h | ||
| dmabrg.h | ||
| dwarf.h | ||
| elf.h | ||
| entry-macros.S | ||
| extable.h | ||
| fb.h | ||
| fixmap.h | ||
| flat.h | ||
| fpu.h | ||
| freq.h | ||
| ftrace.h | ||
| futex-cas.h | ||
| futex-irq.h | ||
| futex-llsc.h | ||
| futex.h | ||
| gpio.h | ||
| hardirq.h | ||
| hd64461.h | ||
| heartbeat.h | ||
| hugetlb.h | ||
| hw_breakpoint.h | ||
| hw_irq.h | ||
| i2c-sh7760.h | ||
| io.h | ||
| io_generic.h | ||
| io_noioport.h | ||
| io_trapped.h | ||
| irq.h | ||
| irqflags.h | ||
| kdebug.h | ||
| kexec.h | ||
| kgdb.h | ||
| kprobes.h | ||
| linkage.h | ||
| machvec.h | ||
| mmiowb.h | ||
| mmu.h | ||
| mmu_context.h | ||
| mmu_context_32.h | ||
| mmzone.h | ||
| module.h | ||
| page.h | ||
| pci.h | ||
| perf_event.h | ||
| pgalloc.h | ||
| pgtable-2level.h | ||
| pgtable-3level.h | ||
| pgtable.h | ||
| pgtable_32.h | ||
| platform_early.h | ||
| posix_types.h | ||
| processor.h | ||
| processor_32.h | ||
| ptrace.h | ||
| ptrace_32.h | ||
| push-switch.h | ||
| reboot.h | ||
| romimage-macros.h | ||
| rtc.h | ||
| seccomp.h | ||
| sections.h | ||
| segment.h | ||
| setup.h | ||
| sfp-machine.h | ||
| sh7760fb.h | ||
| sh_bios.h | ||
| shmparam.h | ||
| siu.h | ||
| smc37c93x.h | ||
| smp-ops.h | ||
| smp.h | ||
| sparsemem.h | ||
| spi.h | ||
| spinlock-cas.h | ||
| spinlock-llsc.h | ||
| spinlock.h | ||
| spinlock_types.h | ||
| sram.h | ||
| stackprotector.h | ||
| stacktrace.h | ||
| string.h | ||
| string_32.h | ||
| suspend.h | ||
| switch_to.h | ||
| switch_to_32.h | ||
| syscall.h | ||
| syscall_32.h | ||
| syscalls.h | ||
| syscalls_32.h | ||
| thread_info.h | ||
| timex.h | ||
| tlb.h | ||
| tlbflush.h | ||
| topology.h | ||
| traps.h | ||
| traps_32.h | ||
| types.h | ||
| uaccess.h | ||
| uaccess_32.h | ||
| unaligned-sh4a.h | ||
| unaligned.h | ||
| uncached.h | ||
| unistd.h | ||
| unwinder.h | ||
| user.h | ||
| vermagic.h | ||
| vga.h | ||
| vmalloc.h | ||
| vmlinux.lds.h | ||
| watchdog.h | ||
| word-at-a-time.h | ||