On 2025/1/7 17:57, Kevin Brodsky wrote:
On 06/01/2025 04:49, Qi Zheng wrote:
[...]
Once this is done, we should be able to replace all those confusing
calls to tlb_remove_page() on PTPs with tlb_remove_table() and remove
the explicit call to pagetable_dtor(). AIUI this is essentially what
Peter suggested on v3 [2].
Since this patch series is mainly for bug fix, I think that these things
can be done in separate patch series later.
Sure that's fair.
[...]
Or can we just not let tlb_remove_table() fall back to
tlb_remove_page()? Like the following:
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index a59205863f431..354ffaa4bd120 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -195,8 +195,6 @@
* various ptep_get_and_clear() functions.
*/
-#ifdef CONFIG_MMU_GATHER_TABLE_FREE
-
struct mmu_table_batch {
#ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
struct rcu_head rcu;
@@ -219,16 +217,6 @@ static inline void __tlb_remove_table(void *table)
extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
-#else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */
-
-/*
- * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have
page based
- * page directories and we can use the normal page batching to free
them.
- */
-#define tlb_remove_table(tlb, page) tlb_remove_page((tlb), (page))
We still need a different implementation of tlb_remove_table() in this
case. We could define it inline here:
static inline void tlb_remove_table(struct mmu_gather *tlb, void *table)
{
struct page *page = table;
pagetable_dtor(page_ptdesc(page));
tlb_remove_page(page);
}
Right. As I said above, will add this to the updated patch #8.
I think it would be preferable to make it a standalone patch, because
this is a change to generic code that could in principle impact other
arch's too.
Agree, I have done that:
```
Author: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Date: Fri Dec 13 17:13:48 2024 +0800
mm: pgtable: completely move pagetable_dtor() to generic
tlb_remove_table()
For the generic tlb_remove_table(), it is implemented in the
following two
forms:
1) CONFIG_MMU_GATHER_TABLE_FREE is enabled
tlb_remove_table
--> generic __tlb_remove_table()
2) CONFIG_MMU_GATHER_TABLE_FREE is disabled
tlb_remove_table
--> tlb_remove_page
For case 1), the pagetable_dtor() has already been moved to generic
__tlb_remove_table().
For case 2), now only arm will call
tlb_remove_table()/tlb_remove_ptdesc()
when CONFIG_MMU_GATHER_TABLE_FREE is disabled. Let's move
pagetable_dtor()
completely to generic tlb_remove_table(), so that the architectures can
follow more easily.
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index b8eebdb598631..ea4fbe7b17f6f 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -34,10 +34,6 @@ __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long addr)
{
struct ptdesc *ptdesc = page_ptdesc(pte);
-#ifndef CONFIG_MMU_GATHER_TABLE_FREE
- pagetable_dtor(ptdesc);
-#endif
-
#ifndef CONFIG_ARM_LPAE
/*
* With the classic ARM MMU, a pte page has two corresponding pmd
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 69de47c7ef3c5..53ae7748f555b 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -220,14 +220,20 @@ static inline void __tlb_remove_table(void *table)
extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
-#else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */
+#else /* !CONFIG_MMU_GATHER_TABLE_FREE */
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page
*page);
/*
* Without MMU_GATHER_TABLE_FREE the architecture is assumed to have
page based
* page directories and we can use the normal page batching to free them.
*/
-#define tlb_remove_table(tlb, page) tlb_remove_page((tlb), (page))
+static inline void tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ struct page *page = (struct page *)table;
+ pagetable_dtor(page_ptdesc(page));
+ tlb_remove_page(tlb, page);
+}
#endif /* CONFIG_MMU_GATHER_TABLE_FREE */
#ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
```
and will send v5 later.
Thanks!
- Kevin
