#8224: Excessive system time -- new IO manager problem? -------------------------------------+------------------------------------- Reporter: rrnewton | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Runtime System | Version: 7.7 Resolution: | Keywords: IO Manager, Operating System: Linux | System Time Type of failure: Runtime | Architecture: x86_64 (amd64) performance bug | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------- Comment (by AndreasVoellmy): Good idea. I still see about the same amount of system time. The {{{__ticket_spin_lock}}} is still at the top: {{{ Events: 1K cycles # # Overhead Command Shared Object Symbol # ........ ............... .................. ................................... # 34.41% excessive_syste [kernel.kallsyms] [k] __ticket_spin_lock 11.94% excessive_syste [kernel.kallsyms] [k] default_send_IPI_mask_sequence_phys 4.48% excessive_syste [kernel.kallsyms] [k] update_sd_lb_stats 3.39% excessive_syste [kernel.kallsyms] [k] native_write_msr_safe 1.86% excessive_syste [kernel.kallsyms] [k] __slab_free 1.85% excessive_syste [kernel.kallsyms] [k] idle_cpu 1.55% excessive_syste libc-2.15.so [.] 0x7e175 1.39% excessive_syste [kernel.kallsyms] [k] perf_event_alloc 1.36% excessive_syste [kernel.kallsyms] [k] dequeue_task_fair 1.21% :47802 [kernel.kallsyms] [k] page_remove_rmap 1.09% excessive_syste [kernel.kallsyms] [k] mmap_region 0.99% excessive_syste [kernel.kallsyms] [k] __init_waitqueue_head 0.94% excessive_syste [kernel.kallsyms] [k] memset 0.92% excessive_syste [kernel.kallsyms] [k] do_futex 0.90% excessive_syste [kernel.kallsyms] [k] perf_event_mmap_ctx 0.89% excessive_syste [kernel.kallsyms] [k] kmem_cache_alloc_trace 0.87% excessive_syste libpthread-2.15.so [.] __deallocate_stack 0.86% excessive_syste excessive_system [.] waitCondition 0.86% excessive_syste [kernel.kallsyms] [k] __rwsem_do_wake 0.85% excessive_syste [kernel.kallsyms] [k] get_page_from_freelist 0.84% excessive_syste [kernel.kallsyms] [k] find_vma 0.84% excessive_syste excessive_system [.] s6t3_info 0.83% excessive_syste [kernel.kallsyms] [k] sys_read 0.82% excessive_syste [kernel.kallsyms] [k] kfree 0.78% excessive_syste [kernel.kallsyms] [k] __raw_write_unlock_irq.constprop.31 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8224#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler