On 2015/06/16 23:46, Arnaldo Carvalho de Melo wrote: > Em Tue, Jun 16, 2015 at 08:50:57PM +0900, Masami Hiramatsu escreveu: >> When the last part of converted events are blacklisted or out-of-text, >> those are skipped and perf probe doesn't show usage examples. >> This fixes it to show the example even if the last part of event list >> is skipped. >> >> E.g. without this patch, events are added, but suddenly end; > > End what? Stop being added?
"End without the last message", I meant. > I.e. not all eligible events are added? From > your description the problem seems to be that that last message: "You > can now use it..." is not presented, but here, without this patch, it > is: I see, actually, this happens only if the skipped symbols ( vfs_caches_init_early or vfs_caches_init) are placed at the end of the matched symbol list. On Ubuntu 15.04 kernel, it doesn't have vfs_load_quota_inode etc. and the vfs_caches_init is the last part of the matched list. Since it is hard to reproduce, I've added a Note on the end of description :) ---- >> >> Note that this can be reproduced ONLY IF the vfs_caches_init* >> is the last part of matched symbol list. I've checked this happens >> on "3.19.0-generic #18-Ubuntu" kernel binary. >> ---- To reproduce this bug, you need to find a good symbol matching pattern which (1) matches both of valid function in .text and invalid function in .inittext (2) invalid one must be on the end of matched function list. I fortunately hit such pattern and found this bug, but it depends on the kernel binary. [...] > I.e. the only problem I found was this: > > [root@zoo ~]# time perf probe -l > /dev/null > > real 0m15.408s > user 0m14.892s > sys 0m0.534s > [root@zoo ~]# > [root@zoo ~]# perf stat perf probe -l > /dev/null > > Performance counter stats for 'perf probe -l': > > 15256.588897 task-clock (msec) # 1.001 CPUs utilized > > 116 context-switches # 0.008 K/sec > > 4 cpu-migrations # 0.000 K/sec > > 230,720 page-faults # 0.015 M/sec > > 47,830,405,530 cycles # 3.135 GHz > > 43,974,134,505 stalled-cycles-frontend # 91.94% frontend cycles > idle > <not supported> stalled-cycles-backend > 11,540,587,038 instructions # 0.24 insns per cycle > > # 3.81 stalled cycles > per insn > 2,807,769,592 branches # 184.037 M/sec > > 20,087,075 branch-misses # 0.72% of all branches > > > 15.240796324 seconds time elapsed > > [root@zoo ~]# > > Can you check why it takes so long and check the need for this patch? It is because perf probe -l is not optimized to show a lot of probes yet. It initializes and loads debuginfo for each probe. I guess we can reuse debuginfo among them. let me try... Thank you, -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
