[PATCH v5 01/17] Revert "mm: pgtable: make ptlock be freed by RCU"
From: Qi Zheng <hidden>
Date: 2025-01-08 06:59:31
Also in:
linux-arm-kernel, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linux-um, linuxppc-dev, lkml, loongarch, sparclinux
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
This reverts commit 2f3443770437e49abc39af26962d293851cbab6d. Signed-off-by: Qi Zheng <redacted> Reviewed-by: Kevin Brodsky <redacted> --- include/linux/mm.h | 2 +- include/linux/mm_types.h | 9 +-------- mm/memory.c | 22 ++++++---------------- 3 files changed, 8 insertions(+), 25 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d61b9c7a3a7b0..c49bc7b764535 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -2925,7 +2925,7 @@ void ptlock_free(struct ptdesc *ptdesc); static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc) { - return &(ptdesc->ptl->ptl); + return ptdesc->ptl; } #else /* ALLOC_SPLIT_PTLOCKS */ static inline void ptlock_cache_init(void)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 90ab8293d714a..6b27db7f94963 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h@@ -434,13 +434,6 @@ FOLIO_MATCH(flags, _flags_2a); FOLIO_MATCH(compound_head, _head_2a); #undef FOLIO_MATCH -#if ALLOC_SPLIT_PTLOCKS -struct pt_lock { - spinlock_t ptl; - struct rcu_head rcu; -}; -#endif - /** * struct ptdesc - Memory descriptor for page tables. * @__page_flags: Same as page flags. Powerpc only.
@@ -489,7 +482,7 @@ struct ptdesc { union { unsigned long _pt_pad_2; #if ALLOC_SPLIT_PTLOCKS - struct pt_lock *ptl; + spinlock_t *ptl; #else spinlock_t ptl; #endif
diff --git a/mm/memory.c b/mm/memory.c
index b9b05c3f93f11..9423967b24180 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -7034,34 +7034,24 @@ static struct kmem_cache *page_ptl_cachep; void __init ptlock_cache_init(void) { - page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(struct pt_lock), 0, + page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0, SLAB_PANIC, NULL); } bool ptlock_alloc(struct ptdesc *ptdesc) { - struct pt_lock *pt_lock; + spinlock_t *ptl; - pt_lock = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL); - if (!pt_lock) + ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL); + if (!ptl) return false; - ptdesc->ptl = pt_lock; + ptdesc->ptl = ptl; return true; } -static void ptlock_free_rcu(struct rcu_head *head) -{ - struct pt_lock *pt_lock; - - pt_lock = container_of(head, struct pt_lock, rcu); - kmem_cache_free(page_ptl_cachep, pt_lock); -} - void ptlock_free(struct ptdesc *ptdesc) { - struct pt_lock *pt_lock = ptdesc->ptl; - - call_rcu(&pt_lock->rcu, ptlock_free_rcu); + kmem_cache_free(page_ptl_cachep, ptdesc->ptl); } #endif
--
2.20.1