lkml.org 
[lkml]   [2009]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/5] x86: fix pageattr handling for remap percpu allocator
>>> Tejun Heo <tj@kernel.org> 15.05.09 06:28 >>>
>@@ -742,6 +744,27 @@ static int cpa_process_alias(struct cpa_data *cpa)
> }
> #endif
>
>+ /*
>+ * If the PMD page was partially used for per-cpu remapping,
>+ * the remapped area needs to be split and modified. Note
>+ * that the partial recycling only happens at the tail of a
>+ * partially used PMD page, so touching single PMD page is
>+ * always enough.
>+ */
>+ remapped = pcpu_pmd_remapped((void *)vaddr);

vaddr here is the passed-in address, but in order for the lookup to be positive
it needs to be the canonical address (i.e. the one pointing into the 1:1 mapping),
i.e. __va(cpa->pfn << PAGE_SHIFT), just like temp_cpa_vaddr gets calculated
earlier in the same function.

>+ if (remapped) {
>+ int max_pages = PFN_DOWN(PMD_SIZE - (vaddr & ~PMD_MASK));
>+
>+ alias_cpa = *cpa;
>+ temp_cpa_vaddr = (unsigned long)remapped;
>+ alias_cpa.vaddr = &temp_cpa_vaddr;
>+ alias_cpa.numpages = min(alias_cpa.numpages, max_pages);
>+ alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
>+ ret = __change_page_attr_set_clr(&alias_cpa, 0);
>+ if (ret)
>+ return ret;
>+ }
>+
> return 0;
> }

Sorry for not having spotted this yesterday,
Jan



\
 
 \ /
  Last update: 2009-05-15 10:01    [W:0.119 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site