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 <panand@xxxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
