Hi David,
Thanks very much for the detailed comments and explanations!
在 2024/9/2 21:45, David Hildenbrand 写道:
On 02.09.24 14:24, Rong Qianfeng wrote:
Reserved pages are basically non-lru pages. This kind of memory can't be
used as migration sources and targets, skip it can bring some
performance
benefits.
Any numbers? :)
I am still thinking about how to design test cases. If you have any good
suggestions, please tell me. Thank you very much.
+
+extern void set_pageblock_skip_range(unsigned long start_pfn,
+ unsigned long end_pfn);
two tabs indentation on the second line please. Applies to all others as
well.
Got it. Will do in the next version.
+ /*
+ * We set the PB_migrate_skip in
+ * reserve_bootmem_region() for cma
+ * memory, clear it now.
You can fit this easily into less lines
Will do in the next version. Thanks.
+ /*
+ * Clear PB_migrate_skip if the memory have released
+ * to the buddy system.
+ */
... after freeing the memory to the buddy."
And maybe
if (pages) {
if (s)
pr_info("Freeing %s memory: %ldK\n", s, K(pages));
clear_pageblock_skip_range(...)
}
+ clear_pageblock_skip_range(page_to_pfn(virt_to_page(start)),
+ page_to_pfn(virt_to_page(end)));
+
PHYS_PFN(virt_to_phys(start)) might look a bit nicer, not need to
get pages involved. virt_to_pfn might be even better(), but it's
not available on all archs I think.
You are right, I tried to use virt_to_pfn, but later found out that it
is not
supported on x86.
What about free_reserved_page() ? There might be more, though
(kimage_free_pages()). You have to take a look at all functions where we
clear PageReserved.
Thanks for your reminder, I found that I missed a lot of functions.
Maybe a better choice is to clear PB_migrate_skip in free_reserved_page()
to reduce the amount of modification.
Best Regards,
Qianfeng
