From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hidetoshi Seto Date: Fri, 13 Jul 2007 01:27:30 +0000 Subject: Re: [RFC][PATCH] fsys_gettimeofday leaps days if it runs with nojitter Message-Id: <4696D502.7010701@jp.fujitsu.com> List-Id: References: <468CA2D6.40204@jp.fujitsu.com> In-Reply-To: <468CA2D6.40204@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Luck, Tony wrote: >>> I'm guessing here ... I haven't cross-checked with the architects. >> I'll be glad if we can get a comment from Intel's architects. > > I talked this through with an architect, and I'm right. In the > sequence: > > ld4.acq rM = [rN] > ;; > mov rP = ar.itc > > there are no dependencies, so the read of ar.itc can occur > "IMMEDIATELY after the load issues". > > Consuming the result of the load in between will create a > dependency ... so the timestamp will be taken as we want it, > after the load. > > So I can apply this patch (moving the "and r28 = ~1,r28"). Thank you for checking it. > What other time patches are you still pushing? The time > interpolator changes that were predicted still look like > they are pending somewhere (kernel/timer.c hasn't been > changed). > > -Tony I don't know the current status of Bob's patches... I hope you don't mind applying my small patches before Bob's. Here are 2 pending patches I'm pushing : - [PATCH] ia64: Scalability improvement of gettimeofday with jitter compensation - [PATCH] fsys_gettimeofday leaps days if it runs with nojitter I confirmed that these 2 can be applied to 2.6.22 (with some offset). Let me know if you need refreshed ones. Thanks, H.Seto