Re: [RFC v2 PATCH 4/4] mm: pre zero out free pages to speed up page allocation for __GFP_ZERO
From: Matthew Wilcox <willy@infradead.org>
Date: 2021-01-04 19:30:50
Also in:
linux-mm, lkml
On Mon, Jan 04, 2021 at 11:19:13AM -0800, Dave Hansen wrote:
On 12/21/20 8:30 AM, Liang Li wrote:quoted
--- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h@@ -137,6 +137,9 @@ enum pageflags { #endif #ifdef CONFIG_64BIT PG_arch_2, +#endif +#ifdef CONFIG_PREZERO_PAGE + PG_zero, #endif __NR_PAGEFLAGS,I don't think this is worth a generic page->flags bit. There's a ton of space in 'struct page' for pages that are in the allocator. Can't we use some of that space?
I was going to object to that too, but I think the entire approach is flawed and needs to be thrown out. It just nukes the caches in extremely subtle and hard to measure ways, lowering overall system performance. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization