On Tue, Jun 17, 2014 at 08:10:01AM +0200, Petr Tesarik wrote: > On Thu, 12 Jun 2014 17:04:36 +0200 > Petr Tesarik <ptesarik at suse.cz> wrote: > > > On Wed, 11 Jun 2014 13:24:22 -0400 > > Vivek Goyal <vgoyal at redhat.com> wrote: > > > > > On Wed, Jun 11, 2014 at 01:20:42PM +0200, Petr Tesarik wrote: > > > > On Tue, 10 Jun 2014 11:35:54 -0400 > > > > Vivek Goyal <vgoyal at redhat.com> wrote: > > > > > > > > > On Mon, Jun 09, 2014 at 03:31:53PM -0700, Andrew Morton wrote: > > > > > > > > > > > > > > > > > > Guys, could you please review this one? > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > From: Petr Tesarik <ptesarik at suse.cz> > > > > > > Subject: kexec: save PG_head_mask in VMCOREINFO > > > > > > > > > > > > To allow filtering of huge pages, makedumpfile must be able to identify > > > > > > them in the dump. This can be done by checking the appropriate page flag, > > > > > > so communicate its value to makedumpfile through the VMCOREINFO interface. > > > > > > > > > > > > There's only one small catch. Depending on how many page flags are > > > > > > available on a given architecture, this bit can be called PG_head or > > > > > > PG_compound. > > > > > > > > > > > > I sent a similar patch back in 2012, but Eric Biederman did not like using > > > > > > an #ifdef. So, this time I'm adding a common symbol (PG_head_mask) > > > > > > instead. > > > > > > > > > > > > See https://lkml.org/lkml/2012/11/28/91 for the previous version. > > > > > > > > > > > > > > > > Hi Petr, > > > > > > > > > > I went through previous conversation and personally I like that patch > > > > > better. > > > > > > > > > > We already have so many exports in vmcoreinfo which are conditional > > > > > based on config options. Adding one more should be just fine. And as > > > > > you said that it should not bitrot as it will most likely lead > > > > > to complication failures if things shift around. > > > > > > > > > > Does this patch compile with !CONFIG_PAGEFLAGS_EXTENDED. I did not see > > > > > a definition of PG_head_mask in that case. > > > > > > > > With !CONFIG_PAGEFLAGS_EXTENDED, the definition of PG_head_mask is > > > > already there (and has been for quite some time). > > > > > > Oh.., I had not noticed that. Thanks. > > > > > > > > > > > > So I would say post your patch again, I will ack it. CC Eric and hopefully > > > > > he does not have any objections to it. > > Oh, it seems you're still waiting for Eric's opinion, but I didn't > notice that he wasn't in Cc yet. That was in the context of when I said repost the old patch. Later I agreed to existing patch (The one with PG_head_mask) and I have acked it. Thanks Vivek
