>-----Original Message----- >From: Steven Rostedt <rost...@goodmis.org> >Sent: 06 January 2025 22:12 >To: Shiju Jose <shiju.j...@huawei.com> >Cc: mhira...@kernel.org; mathieu.desnoy...@efficios.com; linux-trace- >ker...@vger.kernel.org; linux-ker...@vger.kernel.org; Linuxarm ><linux...@huawei.com>; Jonathan Cameron ><jonathan.came...@huawei.com>; tanxiaofei <tanxiao...@huawei.com>; >Zengtao (B) <prime.z...@hisilicon.com> >Subject: Re: [PATCH 1/1] tracing: Support reading trace event format file >larger >than PAGE_SIZE > >On Mon, 6 Jan 2025 18:15:36 +0000 >Shiju Jose <shiju.j...@huawei.com> wrote: > >> >You see, it requires multiple reads to pull in an entire kernel >> >pseudo file. None of those reads are greater than PAGE_SIZE. Why >> >should trace format files be any different? >> Thanks for the reply. >> Yes. I had a fix/workaround in the userspace rasdaemon with multiple >> reads like above as reported previously in the following thread. >> https://lore.kernel.org/lkml/3c9808a694d242cab35bab67602edebf@huawei.c >> om/ However thought a solution in the common kernel code for the >> format file may be better. I will go ahead with the user space >> solution. > >That would make it different than every other pseudo file in the kernel. I >rather >not do that. > >> >> Also shared an information in the above thread about libtraceevent >> __parse_event() does not return error when parse_format() fail with >> incomplete formt data, which resulted initialization for the trace event does >not fail in the user space tool. > >Hmm, can you send me the the format file that failed? > >Just the output of "cat /sys/kernel/tracing/events/<system>/<event>/format" >will do.
Please find attached format file, which might have failed to parse because of the unsupported formats in the libtraceevent you mentioned in the following thread. https://lore.kernel.org/lkml/20241127104132.6c172...@gandalf.local.home/#t Please find the improvement in the libraceevent which I mentioned for not returning error when parsing failed, =========================================== diff --git a/src/event-parse.c b/src/event-parse.c index 0427061..b9264cb 100644 --- a/src/event-parse.c +++ b/src/event-parse.c @@ -7905,9 +7905,14 @@ __parse_event(struct tep_handle *tep, const char *buf, unsigned long size, const char *sys) { - int ret = parse_format(eventp, tep, buf, size, sys); - struct tep_event *event = *eventp; + int ret; + struct tep_event *event; + + ret = parse_format(eventp, tep, buf, size, sys); + if (ret) + return ret; + event = *eventp; if (event == NULL) return ret; ========================================= > >-- Steve Thanks, Shiju
format_cxl_general_media
Description: format_cxl_general_media
