From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel.Thibault@drdc-rddc.gc.ca (Thibault, Daniel) Date: Thu, 6 Feb 2014 20:18:27 +0000 Subject: [lttng-dev] sched_switch event Message-ID: <48CF5AC71E61DB46B70D0F388054EFFD267DFB0B@VAL-E-02.valcartier.drdc-rddc.gc.ca> -----Message d'origine----- > In linux-source-3.2.0/include/trace/events/sched.h, or > linux-headers-3.2.0-53/include/trace/events/sched.h, or > lttng-modules/instrumentation/events/mainline/sched.h, > we have in part: > > TP_fast_assign( > memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); > __entry->prev_pid = prev->pid; > __entry->prev_prio = prev->prio; > __entry->prev_state = __trace_sched_switch_state(prev); > memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); > __entry->next_pid = next->pid; > __entry->next_prio = next->prio; > ), Scratch that, lttng-modules/instrumentation/events/lttng-module/sched.h has the same code, and I now realise the TP_fast_assign is not switching the prev_comm and next_comm fields (it is correctly mapping __entry->next_comm to next->comm), it's just that the copies are declared out of order. TP_fast_assign is essentially a parallelised process. Sorry about the false alarm. Daniel U. Thibault Protection des syst?mes et contremesures (PSC) | Systems Protection & Countermeasures (SPC) Cyber s?curit? pour les missions essentielles (CME) | Mission Critical Cyber Security (MCCS) R & D pour la d?fense Canada - Valcartier (RDDC Valcartier) | Defence R&D Canada - Valcartier (DRDC Valcartier) 2459 route de la Bravoure Qu?bec QC? G3J 1X5 CANADA Vox?: (418) 844-4000 x4245 Fax?: (418) 844-4538 NAC?: 918V QSDJ Gouvernement du Canada?| Government of Canada