----- Original Message ----- > From: "Dave Hansen" <dave.hansen@xxxxxxxxx> > To: "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx>, "Jerome Marchand" <jmarchan@xxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > Sent: Thursday, November 7, 2013 12:49:54 AM > Subject: Re: [PATCH v4 2/2] mm: allow to set overcommit ratio more precisely > > On 11/06/2013 02:33 PM, Andrew Morton wrote: > > On Wed, 6 Nov 2013 03:42:20 -0500 (EST) Jerome Marchand > > <jmarchan@xxxxxxxxxx> wrote: > >> That was my first version of this patch (actually "kbytes" to avoid > >> overflow). > >> Dave raised the issue that it silently breaks the user interface: > >> overcommit_ratio is zero while the system behaves differently. > > > > I don't understand that at all. We keep overcommit_ratio as-is, with > > the same default values and add a different way of altering it. That > > should be back-compatible? > > Reading the old thread, I think my main point was that we shouldn't > output overcommit_ratio=0 when overcommit_bytes>0. We need to round up > for numbers less than 1 so that folks don't think overcommit_ratio is _off_. This is not how current *bytes work. Also the *ratio and *bytes value would diverge if the amount of memory changes (e.g. memory hotplug). > > I was really just trying to talk you in to cramming the extra precision > in to the _existing_ sysctl. :) I don't think bytes vs. ratio is really > that big of a deal. > If everybody agrees on overcommit_kbytes, I can resend my original patch. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>