From 46df8e73a4a3f1445f2a8429111e72ede1f4d291 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 21 Mar 2024 14:24:45 +0000 Subject: mm: free up PG_slab Reclaim the Slab page flag by using a spare bit in PageType. We are perennially short of page flags for various purposes, and now that the original SLAB allocator has been retired, SLUB does not use the mapcount/page_type field. This lets us remove a number of special cases for ignoring mapcount on Slab pages. [willy@infradead.org: update vmcoreinfo] Link: https://lkml.kernel.org/r/ZgGV-O8WYQ_83kxp@casper.infradead.org Link: https://lkml.kernel.org/r/20240321142448.1645400-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Hildenbrand Cc: Miaohe Lin Cc: Muchun Song Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- kernel/vmcore_info.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c index 23c125c2e243..1d5eadd9dd61 100644 --- a/kernel/vmcore_info.c +++ b/kernel/vmcore_info.c @@ -198,7 +198,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_NUMBER(PG_private); VMCOREINFO_NUMBER(PG_swapcache); VMCOREINFO_NUMBER(PG_swapbacked); - VMCOREINFO_NUMBER(PG_slab); +#define PAGE_SLAB_MAPCOUNT_VALUE (~PG_slab) + VMCOREINFO_NUMBER(PAGE_SLAB_MAPCOUNT_VALUE); #ifdef CONFIG_MEMORY_FAILURE VMCOREINFO_NUMBER(PG_hwpoison); #endif -- cgit v1.2.3