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Wed, 27 May 2020 11:52:51 -0700 (PDT) Date: Wed, 27 May 2020 14:52:49 -0400 From: Peter Xu To: Cornelia Huck Subject: Re: [PATCH] hw/vfio/common: Trace in which mode a IOMMU is opened Message-ID: <20200527185249.GI1194141@xz-x1> References: <20200526173542.28710-1-philmd@redhat.com> <6c7c445d-0335-f67d-bb72-5b0c046bb247@redhat.com> <24f88212-9b32-b6dc-fcd4-685cde8bf5d7@redhat.com> <864ac8ab-e21e-393e-d1eb-08b3c4579bbf@redhat.com> <20200527161603.GF1194141@xz-x1> <3e364895-e5e5-09fe-ee8c-782f3632e2b8@redhat.com> <20200527165330.GG1194141@xz-x1> <20200527190651.2a9ee6ea.cohuck@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200527190651.2a9ee6ea.cohuck@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.81; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/27 00:45:05 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Auger Eric , Alex Williamson , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, May 27, 2020 at 07:06:51PM +0200, Cornelia Huck wrote: > Personally, I find traces to be quite handy, and it's nice if you can > just enable more of them if they are in your debugging workflow anyway. > Probably boils down to a matter of preference :) Totally agree. I am actually a heavy user of QEMU tracing system, just like the rest of the tracing tools all over the world... :) IMHO the difference between a tracepoint and a manual printf() is majorly the reusablility part - if a debugging printf() is likely to be reused in the future, then it is a good tracepoint candidate. Thanks, -- Peter Xu