Messages in this thread | | | Date | Mon, 18 Oct 2010 09:44:47 -0700 | Subject | Re: ima: use of radix tree cache indexing == massive waste of memory? | From | Ryan Ware <> |
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On Sun, Oct 17, 2010 at 11:52 AM, Christoph Hellwig <hch@infradead.org> wrote: > On Sun, Oct 17, 2010 at 03:59:20PM +0200, Peter Zijlstra wrote: >> Well, it does suck it needs to bloat data and code when its effectively >> disabled. Isn't there a way to gather this data before we enable it, eg. >> scan the files list on enable or somesuch? >> >> I mean, if you mandate an external storage you might as well extend >> struct inode, that's cheaper in each respect. > > That's in fact what it did initially. While IBM claimed it would never > be enabled in distros and this would be fine I feared this would not be > true and told them to not make it have overhead if compiled in but not > used.
Isn't it up to distros themselves to decide if this feature should be enabled? I bring this up because we are intending to include this turned on by default in the MeeGo kernel for the 1.2 release next year.
I understand there are some technical concerns regarding performance. We should figure out how to resolve those. That said, upstream is the right place for this.
Ryan
> Turns out I wa right in my fear that IBM pressured distros to enable > it anyway. And turns out that I should have verified they didn't > actually mess it up instead of expecting people to get such trivial > things right. > >> Me, I'm henceforth making sure to have CONFIG_IMA disabled... > > Yeah. > >> > but it doesn't >> > help the fact that the suggested structure for storage (the radix >> > tree) is apparently quite inefficient. I'd love to hear other >> > suggestions for a better structure.... >> >> radix tree is efficient for dense sets, not sparse sets. > > Which actually works just fine for inodes on many filesystems if you > use the right key. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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