On Sat, Sep 16, 2017 at 11:47:56AM +0200, Thomas Gleixner wrote: > On Fri, 8 Sep 2017, Eric Dumazet wrote: > > On Fri, 2017-09-08 at 11:55 -0700, Eduardo Valentin wrote: > > > Hello, > > > > > > On Fri, Sep 08, 2017 at 10:26:45AM -0700, David Miller wrote: > > > > From: David Woodhouse <dw...@infradead.org> > > > > Date: Fri, 08 Sep 2017 18:23:22 +0100 > > > > > > > > > I don't know that anyone's ever tried saying "show me the chapter > > > and > > > > > verse of the documentation" > > > > > > > > Do you know why I brought this up? Because the person I am replying > > > > to told me that the syscall documentation should have suggested this > > > > or that. > > > > > > > > That's why. > > > > > > :-) My intention was for sure not to upset anybody. > > > > > > Just to reiterate, the point of patch is simple, there was a change in > > > behavior in the system call from one kernel version to the other. As I > > > mentioned, I agree that the userspace could use other means to achieve > > > the same, but still the system call behavior has changed. > > > > > > > > > > > So let's concentrate on the other aspects of my reply, ok? > > > > > > I agree. I would prefer to understand here what is the technical > > > reason not to accept these patches other than "use other system > > > calls". > > > > So if we need to replace all 'legacy' timers to high resolution timer, > > because some application was _relying_ on jiffies being kind of precise, > > maybe it is better to revert the change done on legacy timers. > > Which would be a major step back in terms of timer performance and system > disturbance caused by massive recascading operations. > > > Or continue the migration and make them use high res internally. > > > > select() and poll() are the standard way to have precise timeouts, > > it is silly we have to maintain a timeout handling in the datagram fast > > path. > > A few years ago we switched select/poll over to use hrtimers because the > wheel timers were too inaccurate for some operations, so it feels > consequent to switch the timeout in the datagram rcv path over as well. I > agree that the whole timeout magic there feels silly, but unfortunately > it's a documented property of sockets. > > Thanks, > > tglx >
Hello Thomas, Thanks for your comments. This patch has been NACK'ed by David Miller. Is there any other approach to solve this problem with out application code being recompiled? Thanks. -Vallish