Perf将某些直接跳转指令报告为内存访问指令

问题描述 投票:1回答:1

[我使用以下perf命令来采样evince对DRAM的用户空间读取访问:

perf record -d --call-graph dwarf -c 100 -e mem_load_uops_retired.l3_miss:uppp /opt/evince-3.28.4/bin/evince

可以看出,我使用PEBS功能来提高采样的准确性。但是有一些非内存访问被报告为内存访问。例如,这是由perf script报告的采样事件:

evince 20589 16079.401401:        100 mem_load_uops_retired.l3_miss:uppp:     555555860750         5080022 N/A|SNP N/A|TLB N/A|LCK N/A
    555555579939 ev_history_can_go_back+0x19 (/opt/evince-3.28.4/bin/evince)
    5555555862ef ev_window_update_actions_sensitivity+0xa1f (/opt/evince-3.28.4/bin/evince)
    55555558ce4f ev_window_page_changed_cb+0xf (/opt/evince-3.28.4/bin/evince)
    7ffff574510c g_closure_invoke+0x19c (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff575805d signal_emit_unlocked_R+0xf4d (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff5760714 g_signal_emit_valist+0xa74 (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff576112e g_signal_emit+0x8e (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff7140d76 emit_value_changed+0xf6 (inlined)
    7ffff7140d76 adjustment_set_value+0xf6 (inlined)
    7ffff7140d76 gtk_adjustment_set_value_internal+0xf6 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff574510c g_closure_invoke+0x19c (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff5757de7 signal_emit_unlocked_R+0xcd7 (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff575fc7f g_signal_emitv+0x27f (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff7153519 gtk_binding_entry_activate+0x289 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff71539ef binding_activate+0x5f (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff7153b7f gtk_bindings_activate_list+0x17f (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff7154cd8 gtk_bindings_activate_event+0x98 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff7973959 ev_view_key_press_event+0x59 (/opt/evince-3.28.4/lib/libevview3.so.3.0.0)
    7ffff72698f6 _gtk_marshal_BOOLEAN__BOXEDv+0xa6 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff574524f _g_closure_invoke_va+0xbf (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff57603cc g_signal_emit_valist+0x72c (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff576112e g_signal_emit+0x8e (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff73b1533 gtk_widget_event_internal+0x163 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff73d1f0a gtk_window_propagate_key_event+0xfa (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    5555555894b1 ev_window_key_press_event+0x31 (/opt/evince-3.28.4/bin/evince)
    7ffff72698f6 _gtk_marshal_BOOLEAN__BOXEDv+0xa6 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff5745345 _g_closure_invoke_va+0x1b5 (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff57603cc g_signal_emit_valist+0x72c (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff576112e g_signal_emit+0x8e (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5600.4)
    7ffff73b1533 gtk_widget_event_internal+0x163 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff726693e propagate_event+0x21e (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff7268947 gtk_main_do_event+0x7f7 (/usr/lib/x86_64-linux-gnu/libgtk-3.so.0.2200.30)
    7ffff6d79764 _gdk_event_emit+0x24 (/usr/lib/x86_64-linux-gnu/libgdk-3.so.0.2200.30)
    7ffff6da9f91 gdk_event_source_dispatch+0x21 (/usr/lib/x86_64-linux-gnu/libgdk-3.so.0.2200.30)
    7ffff546a416 g_main_dispatch+0x2e6 (inlined)
    7ffff546a416 g_main_context_dispatch+0x2e6 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.5600.4)
    7ffff546a64f g_main_context_iterate+0x1ff (inlined)
    7ffff546a6db g_main_context_iteration+0x2b (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.5600.4)
    7ffff5a2be3c g_application_run+0x1fc (/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0.5600.4)
    555555573707 main+0x447 (/opt/evince-3.28.4/bin/evince)
    7ffff4a91b96 __libc_start_main+0xe6 (/lib/x86_64-linux-gnu/libc-2.27.so)
    555555573899 _start+0x29 (/opt/evince-3.28.4/bin/evince)
ffffffffffffffff [unknown] ([unknown])

[这意味着存在通过功能[[ C0])。此内存指令是以下代码段的最后一行:

0x555555860750

这是跳转到[heap],显然,这不是对地址0x555555579939上的evince的访问。此text报告是否错误?

linux x86-64 performancecounter perf memory-access
1个回答
5
投票

因此,在融合域(发生淘汰的情况下),您确实确实具有带有内存源的单uup比较和分支。请注意,[heap]只是计数,而不是指令。

即使在未融合域中,macro融合的比较/分支实际上也作为单个uop在单个执行单元上执行,但是负载确实必须在单独的端口上执行。 (微融合可节省解码/发出的前端带宽和uop缓存空间,但不能节省后端端口。)

© www.soinside.com 2019 - 2024. All rights reserved.