On 26/08/2015:08:01:21 AM, Jeff Layton wrote: > On Wed, 26 Aug 2015 17:22:25 +0530 > Pratyush Anand <pan...@redhat.com> wrote: > > > Hi Jeff, > > > > Thanks for your review comments. > > > > On 26/08/2015:06:31:03 AM, Jeff Layton wrote: > > > On Tue, 25 Aug 2015 11:34:19 +0530 > > > Pratyush Anand <pan...@redhat.com> wrote: > > > > TP_fast_assign( > > > > __entry->xprt = xprt; > > > > + __entry->addr = > > > > + xprt ? (struct sockaddr *)&xprt->xpt_remote : > > > > NULL; > > > > > > I don't get it. It's not safe to save a pointer to xprt and dereference > > > that in a tracepoint (and I understand why that is), but it is safe to > > > save a pointer to a structure embedded inside of xprt? Shouldn't you be > > > saving a copy of the entire sockaddr struct instead? > > > > As far as "saving of a pointer to a structure embedded inside of xprt" is > > concerned, I do not see any issue. > > > > Its your take that what you want to print as your tracepoint print output. I > > might be missing something.. However, I do not see any value addition in > > printing address of a structure(located in ring buffer) where > > xprt->xpt_remote > > has been copied. > > > > > > > > Ahh, ok -- I think I see the confusion. %pIScp does not print the > > > address of the sockaddr, but instead dereferences the pointer and > > > prints it as a formatted address string. See pointer() in > > > lib/vsprintf.c. You do want to save off a copy of the structure instead. > > > > In my opinion, saving of structure would only be necessary if you want to > > access > > element of the structure xprt->xpt_remote. > > > > ~Pratyush > > That's exactly what %pI does. Look at the pointer() function.
My bad..am a slow learner :( Will send V2. Thanks for explaining. ~Pratyush -- 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/
