On Thu, May 02, 2019 at 04:14:57PM +0200, Martin Schwidefsky wrote:
On Thu, 2 May 2019 06:46:23 -0700 Matthew Wilcox willy@infradead.org wrote:
On Thu, May 02, 2019 at 06:48:46PM +0530, Anshuman Khandual wrote:
Drop the pgtable_t variable from all implementation for pte_fn_t as none of them use it. apply_to_pte_range() should stop computing it as well. Should help us save some cycles.
You didn't add Martin Schwidefsky for some reason. He introduced it originally for s390 for sub-page page tables back in 2008 (commit 2f569afd9c). I think he should confirm that he no longer needs it.
With its 2K pte tables s390 can not deal with a (struct page *) as a reference to a page table. But if there are no user of the apply_to_page_range() API left which actually make use of the token argument we can safely drop it.
Interestingly, I don't think there ever was a user which used that argument. Looking at your 2f56 patch, you only converted one function (presumably there was only one caller of apply_to_page_range() at the time), and it didn't u se any of the arguments. Xen was the initial user, and the two other functions they added also didn't use that argument.
Looking at a quick sample of users added since, none of them appear to have ever used that argument. So removing it seems best.
Acked-by: Matthew Wilcox willy@infradead.org