[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 3 of 3] xen: sched_credit: add some tracing



On 05/12/12 11:54, Dario Faggioli wrote:
On Tue, 2012-12-04 at 19:10 +0000, George Dunlap wrote:
On 03/12/12 16:35, Dario Faggioli wrote:
+            /* Avoid TRACE_* to avoid a lot of useless !tb_init_done checks */
+            for_each_cpu(cpu, &mask)
+            {
+                struct {
+                    unsigned cpu:8;
+                } d;
+                d.cpu = cpu;
+                trace_var(TRC_CSCHED_TICKLE, 0,
+                          sizeof(d),
+                          (unsigned char*)&d);
Why not just TRC_1D()?

As I tried to explain in the comment, I just wanted to avoid checking
for !tb_init_done more than once, as this happens within a loop and, at
least potentially, there may be more CPUs to tickle (and thus more calls
to TRACE_1D). I take this comment of yours as you not thinking that is
something worthwhile, right? If so, I can definitely turn this into a
"standard" TRACE_1D() call.

Oh right -- yeah, no sense in having a duplicate check on tb_init_done; but the struct is still pointless; just passing sizeof(cpu) and &cpu should be prettier (even if the complier will probably optimize it to the same thing).

 -George


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.