Back to bug 2126805
| Who | When | What | Removed | Added |
|---|---|---|---|---|
| Red Hat Bugzilla | 2022-09-14 12:57:12 UTC | Pool ID | sst_pt_perf_debug_rhel_8 | |
| Red Hat One Jira (issues.redhat.com) | 2022-09-14 13:28:36 UTC | Link ID | Red Hat Issue Tracker RHELPLAN-133965 | |
| William Cohen | 2022-09-23 20:38:04 UTC | CC | wcohen | |
| Keywords | Triaged | |||
| William Cohen | 2022-09-23 20:48:28 UTC | Flags | needinfo?(mhavrila) | |
| William Cohen | 2022-09-23 20:56:50 UTC | Keywords | Regression | |
| William Cohen | 2022-09-26 18:15:15 UTC | Flags | needinfo?(mhavrila) | |
| William Cohen | 2022-09-27 18:29:05 UTC | Sub Component | system-version | system-version |
| Component | systemtap | dyninst | ||
| CC | fche | |||
| William Cohen | 2023-04-21 19:27:42 UTC | Sub Component | system-version | system-version |
| Depends On | 2186932 | |||
| Component | dyninst | systemtap | ||
| William Cohen | 2023-04-21 19:41:48 UTC | Status | NEW | ASSIGNED |
| Martin Cermak | 2023-04-24 08:53:38 UTC | QA Contact | qe-baseos-tools-bugs | mcermak |
| William Cohen | 2023-04-24 13:39:30 UTC | Doc Type | If docs needed, set a value | Bug Fix |
| William Cohen | 2023-05-01 13:42:28 UTC | Fixed In Version | systemtap-4.9-1.el8 | |
| Status | ASSIGNED | MODIFIED | ||
| errata-xmlrpc | 2023-05-11 14:31:17 UTC | Status | MODIFIED | ON_QA |
| William Cohen | 2023-05-15 19:47:09 UTC | Doc Text | Cause: The systemtap guru mode liveness analysis uses dyninst to parse binaries. The newer kernels enable mitigation code with CONFIG_RETPOLINE=y which replaces traditional RET machine instructions with jumps to a thunk. This greatly complicates the analysis to determine whether the jump to the thunk is to a target inside the function to a cold section of the same function or to a tail call to another function (the thunk). Consequence: The binary analysis take a much greater amount of time as the analysis needs to examine all the additional edges introduced into the control flow graph (CFG) by the jumps to the thunk. Fix: Systemtap determine when the kernel code is using thunks (CONFIG_RETPOLINE=y) and disables the liveness analysis in those cases. Result: Systemtap scripts using guru mode should compile more quickly. |
|
| Martin Cermak | 2023-05-16 07:12:17 UTC | Status | ON_QA | VERIFIED |
| Jacob Taylor Valdez | 2023-06-20 07:52:35 UTC | Doc Text | Cause: The systemtap guru mode liveness analysis uses dyninst to parse binaries. The newer kernels enable mitigation code with CONFIG_RETPOLINE=y which replaces traditional RET machine instructions with jumps to a thunk. This greatly complicates the analysis to determine whether the jump to the thunk is to a target inside the function to a cold section of the same function or to a tail call to another function (the thunk). Consequence: The binary analysis take a much greater amount of time as the analysis needs to examine all the additional edges introduced into the control flow graph (CFG) by the jumps to the thunk. Fix: Systemtap determine when the kernel code is using thunks (CONFIG_RETPOLINE=y) and disables the liveness analysis in those cases. Result: Systemtap scripts using guru mode should compile more quickly. | .`systemtap` scripts using guru mode now compile more quickly The `systemtap` guru mode liveness analysis uses `dyninst` to parse binaries. Newer kernels enable mitigation code with `CONFIG_RETPOLINE=y`, replacing traditional RET instructions, with jumps to a thunk. As a consequence, binary analysis took a much longer time due to the liveness analysis needing to examine all additional edges of the control flow graph introduced by the jumps to the thunk. With this update, `systemtap` disables liveness analysis when the kernel code is using thunks and, as a result, `systemtap` scripts using guru mode compile more quickly. |
| Flags | needinfo?(fche) | |||
| CC | jvaldez | |||
| Jacob Taylor Valdez | 2023-06-20 07:52:59 UTC | Docs Contact | jvaldez | |
| William Cohen | 2023-06-21 19:59:29 UTC | Flags | needinfo?(fche) | |
| Jacob Taylor Valdez | 2023-08-01 10:08:26 UTC | Flags | needinfo?(fche) | |
| Doc Text | .`systemtap` scripts using guru mode now compile more quickly The `systemtap` guru mode liveness analysis uses `dyninst` to parse binaries. Newer kernels enable mitigation code with `CONFIG_RETPOLINE=y`, replacing traditional RET instructions, with jumps to a thunk. As a consequence, binary analysis took a much longer time due to the liveness analysis needing to examine all additional edges of the control flow graph introduced by the jumps to the thunk. With this update, `systemtap` disables liveness analysis when the kernel code is using thunks and, as a result, `systemtap` scripts using guru mode compile more quickly. | .`systemtap` scripts using guru mode now compile more quickly The `systemtap` guru mode liveness analysis uses the `dyninst` library to parse binaries. Newer kernels enable mitigation code with `CONFIG_RETPOLINE=y`, replacing traditional RET instructions, with jumps to a thunk. As a consequence, binary analysis took a much longer time due to the liveness analysis needing to examine all additional edges of the control flow graph introduced by the jumps to the thunk. With this update, `systemtap` disables liveness analysis when the kernel code is using thunks and, as a result, `systemtap` scripts using guru mode compile more quickly. |
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| William Cohen | 2023-08-01 14:24:39 UTC | Flags | needinfo?(fche) |
Back to bug 2126805