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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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| .. | ||
| .gitignore | ||
| arch_timer.c | ||
| armksyms.c | ||
| asm-offsets.c | ||
| atags.h | ||
| atags_compat.c | ||
| atags_parse.c | ||
| atags_proc.c | ||
| bios32.c | ||
| bugs.c | ||
| cpuidle.c | ||
| crash_dump.c | ||
| debug.S | ||
| devtree.c | ||
| dma-isa.c | ||
| dma.c | ||
| early_printk.c | ||
| efi.c | ||
| elf.c | ||
| entry-armv.S | ||
| entry-common.S | ||
| entry-ftrace.S | ||
| entry-header.S | ||
| entry-v7m.S | ||
| fiq.c | ||
| fiqasm.S | ||
| ftrace.c | ||
| head-common.S | ||
| head-inflate-data.c | ||
| head-nommu.S | ||
| head.S | ||
| hibernate.c | ||
| hw_breakpoint.c | ||
| hyp-stub.S | ||
| insn.c | ||
| io.c | ||
| irq.c | ||
| isa.c | ||
| iwmmxt.S | ||
| jump_label.c | ||
| kgdb.c | ||
| machine_kexec.c | ||
| Makefile | ||
| module-plts.c | ||
| module.c | ||
| opcodes.c | ||
| paravirt.c | ||
| patch.c | ||
| perf_callchain.c | ||
| perf_event_v6.c | ||
| perf_event_v7.c | ||
| perf_event_xscale.c | ||
| perf_regs.c | ||
| pj4-cp0.c | ||
| process.c | ||
| psci_smp.c | ||
| ptrace.c | ||
| reboot.c | ||
| reboot.h | ||
| relocate_kernel.S | ||
| return_address.c | ||
| setup.c | ||
| signal.c | ||
| signal.h | ||
| sigreturn_codes.S | ||
| sleep.S | ||
| smccc-call.S | ||
| smp.c | ||
| smp_scu.c | ||
| smp_tlb.c | ||
| smp_twd.c | ||
| stacktrace.c | ||
| suspend.c | ||
| swp_emulate.c | ||
| sys_arm.c | ||
| sys_oabi-compat.c | ||
| tcm.c | ||
| thumbee.c | ||
| time.c | ||
| topology.c | ||
| traps.c | ||
| unwind.c | ||
| v7m.c | ||
| vdso.c | ||
| vmlinux-xip.lds.S | ||
| vmlinux.lds.S | ||
| xscale-cp0.c | ||