From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39444 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728880AbfJOOAR (ORCPT ); Tue, 15 Oct 2019 10:00:17 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x9FDsD4N130984 for ; Tue, 15 Oct 2019 10:00:16 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2vnd4wwkw7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 15 Oct 2019 10:00:15 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 15 Oct 2019 15:00:13 +0100 Subject: Re: [RFC PATCH 2/4] vfio-ccw: Trace the FSM jumptable References: <20191014180855.19400-1-farman@linux.ibm.com> <20191014180855.19400-3-farman@linux.ibm.com> <96431f2f-774c-0be2-54ef-ebcaa4ae7298@linux.ibm.com> <20191015155339.0d714c75.cohuck@redhat.com> From: Steffen Maier Date: Tue, 15 Oct 2019 16:00:09 +0200 MIME-Version: 1.0 In-Reply-To: <20191015155339.0d714c75.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <4d9b1e87-18be-24f3-5f4d-796442b882a5@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: Eric Farman , Halil Pasic , Jason Herne , Jared Rossi , linux-s390@vger.kernel.org, kvm@vger.kernel.org On 10/15/19 3:53 PM, Cornelia Huck wrote: > On Tue, 15 Oct 2019 12:01:12 +0200 > Steffen Maier wrote: > >> On 10/14/19 8:08 PM, Eric Farman wrote: >>> It would be nice if we could track the sequence of events within >>> vfio-ccw, based on the state of the device/FSM and our calling >>> sequence within it. So let's add a simple trace here so we can >>> watch the states change as things go, and allow it to be folded >>> into the rest of the other cio traces. >>> >>> Signed-off-by: Eric Farman >>> --- >>> drivers/s390/cio/vfio_ccw_private.h | 1 + >>> drivers/s390/cio/vfio_ccw_trace.c | 1 + >>> drivers/s390/cio/vfio_ccw_trace.h | 26 ++++++++++++++++++++++++++ >>> 3 files changed, 28 insertions(+) > > (...) > >>> diff --git a/drivers/s390/cio/vfio_ccw_trace.h b/drivers/s390/cio/vfio_ccw_trace.h >>> index 2a2937a40124..24a8152acfdf 100644 >>> --- a/drivers/s390/cio/vfio_ccw_trace.h >>> +++ b/drivers/s390/cio/vfio_ccw_trace.h >>> @@ -17,6 +17,32 @@ >>> >>> #include >>> >>> +TRACE_EVENT(vfio_ccw_fsm_event, >>> + TP_PROTO(struct subchannel_id schid, int state, int event), >>> + TP_ARGS(schid, state, event), >>> + >>> + TP_STRUCT__entry( >>> + __field(u8, cssid) >>> + __field(u8, ssid) >>> + __field(u16, schno) >>> + __field(int, state) >>> + __field(int, event) >>> + ), >>> + >>> + TP_fast_assign( >>> + __entry->cssid = schid.cssid; >>> + __entry->ssid = schid.ssid; >>> + __entry->schno = schid.sch_no; >>> + __entry->state = state; >>> + __entry->event = event; >>> + ), >>> + >>> + TP_printk("schid=%x.%x.%04x state=%x event=%x", >> >> /sys/kernel/debug/tracing/events](0)# grep -R '%[^%]*x' >> >> Many existing TPs often seem to format hex output with a 0x prefix (either >> explicit with 0x%x or implicit with %#x). Since some of your other TPs also >> output decimal integer values, I wonder if a distinction would help >> unexperienced TP readers. > > I generally agree. However, we explicitly don't want to do that for > schid formatting (as it should match the bus id). For event, it might > become relevant should we want to introduce a high number of new events > in the future (currently, there's a grand total of four events.) Yeah, thanks for clarifying. I meant just state and event, not schid. > >> >>> + __entry->cssid, __entry->ssid, __entry->schno, >>> + __entry->state, >>> + __entry->event) >>> +); >>> + >>> TRACE_EVENT(vfio_ccw_io_fctl, >>> TP_PROTO(int fctl, struct subchannel_id schid, int errno, char *errstr), >>> TP_ARGS(fctl, schid, errno, errstr), >>> >> >> > -- Mit freundlichen Gruessen / Kind regards Steffen Maier Linux on IBM Z Development https://www.ibm.com/privacy/us/en/ IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Matthias Hartmann Geschaeftsfuehrung: Dirk Wittkopp Sitz der Gesellschaft: Boeblingen Registergericht: Amtsgericht Stuttgart, HRB 243294