Re: x86_64: potential critical issue with quicklists and page tablepages

[Linus Torvalds]

On Fri, 21 Sep 2007, Siddha, Suresh B wrote:
>
> git commit 34feb2c83beb3bdf13535a36770f7e50b47ef299 started using quicklists
> for freeing page table pages and removed the usage of tlb_remove_page()
> 
> And looking at quicklist_free() and quicklist_free_page(), on a NUMA platform,
> this can potentially free the page before the corresponding TLB caches
> are flushed.

Hmm? We only add them to the quicklists in the exact same places where we 
*used* to just free them entirely. So I don't see why semantics would have 
changed..

> Can we revert this commit for 2.6.23 and look at this code post 2.6.23?

I'll happily revert it, but I want to understand this better, so more of 
an explanation of the codepath that actually does something wrong, please.

		Linus
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