Re: [PATCH 13/18] asm-generic/tlb: Introduce HAVE_MMU_GATHER_NO_GATHER
Peter Zijlstra writes: > From: Martin Schwidefsky > > Add the Kconfig option HAVE_MMU_GATHER_NO_GATHER to the generic > mmu_gather code. If the option is set the mmu_gather will not > track individual pages for delayed page free anymore. A platform > that enables the option needs to provide its own implementation > of the __tlb_remove_page_size function to free pages. Can we rename this to HAVE_NO_BATCH_MMU_GATHER? > > Cc: npig...@gmail.com > Cc: heiko.carst...@de.ibm.com > Cc: will.dea...@arm.com > Cc: aneesh.ku...@linux.vnet.ibm.com > Cc: a...@linux-foundation.org > Cc: Linus Torvalds > Cc: li...@armlinux.org.uk > Signed-off-by: Martin Schwidefsky > Signed-off-by: Peter Zijlstra (Intel) > Link: http://lkml.kernel.org/r/20180918125151.31744-2-schwidef...@de.ibm.com -aneesh
[PATCH 13/18] asm-generic/tlb: Introduce HAVE_MMU_GATHER_NO_GATHER
From: Martin Schwidefsky
Add the Kconfig option HAVE_MMU_GATHER_NO_GATHER to the generic
mmu_gather code. If the option is set the mmu_gather will not
track individual pages for delayed page free anymore. A platform
that enables the option needs to provide its own implementation
of the __tlb_remove_page_size function to free pages.
Cc: npig...@gmail.com
Cc: heiko.carst...@de.ibm.com
Cc: will.dea...@arm.com
Cc: aneesh.ku...@linux.vnet.ibm.com
Cc: a...@linux-foundation.org
Cc: Linus Torvalds
Cc: li...@armlinux.org.uk
Signed-off-by: Martin Schwidefsky
Signed-off-by: Peter Zijlstra (Intel)
Link: http://lkml.kernel.org/r/20180918125151.31744-2-schwidef...@de.ibm.com
---
arch/Kconfig |3 +
include/asm-generic/tlb.h |9 +++
mm/mmu_gather.c | 107 +-
3 files changed, 70 insertions(+), 49 deletions(-)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -368,6 +368,9 @@ config HAVE_RCU_TABLE_NO_INVALIDATE
config HAVE_MMU_GATHER_PAGE_SIZE
bool
+config HAVE_MMU_GATHER_NO_GATHER
+ bool
+
config ARCH_HAVE_NMI_SAFE_CMPXCHG
bool
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -184,6 +184,7 @@ extern void tlb_remove_table(struct mmu_
#endif
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
/*
* If we can't allocate a page to make a big batch of page pointers
* to work on, then just handle a few from the on-stack structure.
@@ -208,6 +209,10 @@ struct mmu_gather_batch {
*/
#define MAX_GATHER_BATCH_COUNT (1UL/MAX_GATHER_BATCH)
+extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
+ int page_size);
+#endif
+
/*
* struct mmu_gather is an opaque type used by the mm code for passing around
* any data needed by arch specific code for tlb_remove_page.
@@ -254,6 +259,7 @@ struct mmu_gather {
unsigned intbatch_count;
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
struct mmu_gather_batch *active;
struct mmu_gather_batch local;
struct page *__pages[MMU_GATHER_BUNDLE];
@@ -261,6 +267,7 @@ struct mmu_gather {
#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
unsigned int page_size;
#endif
+#endif
};
void arch_tlb_gather_mmu(struct mmu_gather *tlb,
@@ -269,8 +276,6 @@ void tlb_flush_mmu(struct mmu_gather *tl
void arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force);
void tlb_flush_mmu_free(struct mmu_gather *tlb);
-extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
- int page_size);
static inline void __tlb_adjust_range(struct mmu_gather *tlb,
unsigned long address,
--- a/mm/mmu_gather.c
+++ b/mm/mmu_gather.c
@@ -13,6 +13,8 @@
#ifdef HAVE_GENERIC_MMU_GATHER
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
+
static bool tlb_next_batch(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch;
@@ -41,6 +43,56 @@ static bool tlb_next_batch(struct mmu_ga
return true;
}
+static void tlb_batch_pages_flush(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ for (batch = >local; batch && batch->nr; batch = batch->next) {
+ free_pages_and_swap_cache(batch->pages, batch->nr);
+ batch->nr = 0;
+ }
+ tlb->active = >local;
+}
+
+static void tlb_batch_list_free(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch, *next;
+
+ for (batch = tlb->local.next; batch; batch = next) {
+ next = batch->next;
+ free_pages((unsigned long)batch, 0);
+ }
+ tlb->local.next = NULL;
+}
+
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int
page_size)
+{
+ struct mmu_gather_batch *batch;
+
+ VM_BUG_ON(!tlb->end);
+
+#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
+ VM_WARN_ON(tlb->page_size != page_size);
+#endif
+
+ batch = tlb->active;
+ /*
+* Add the page and check if we are full. If so
+* force a flush.
+*/
+ batch->pages[batch->nr++] = page;
+ if (batch->nr == batch->max) {
+ if (!tlb_next_batch(tlb))
+ return true;
+ batch = tlb->active;
+ }
+ VM_BUG_ON_PAGE(batch->nr > batch->max, page);
+
+ return false;
+}
+
+#endif /* HAVE_MMU_GATHER_NO_GATHER */
+
void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
unsigned long start, unsigned long end)
{
@@ -48,12 +100,15 @@ void arch_tlb_gather_mmu(struct mmu_gath
/* Is it from 0 to ~0? */
tlb->fullmm = !(start | (end+1));
+
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
tlb->need_flush_all = 0;
tlb->local.next = NULL;
tlb->local.nr = 0;
tlb->local.max = ARRAY_SIZE(tlb->__pages);
tlb->active = >local;
[PATCH 13/18] asm-generic/tlb: Introduce HAVE_MMU_GATHER_NO_GATHER
From: Martin Schwidefsky
Add the Kconfig option HAVE_MMU_GATHER_NO_GATHER to the generic
mmu_gather code. If the option is set the mmu_gather will not
track individual pages for delayed page free anymore. A platform
that enables the option needs to provide its own implementation
of the __tlb_remove_page_size function to free pages.
Cc: npig...@gmail.com
Cc: heiko.carst...@de.ibm.com
Cc: will.dea...@arm.com
Cc: aneesh.ku...@linux.vnet.ibm.com
Cc: a...@linux-foundation.org
Cc: Linus Torvalds
Cc: li...@armlinux.org.uk
Signed-off-by: Martin Schwidefsky
Signed-off-by: Peter Zijlstra (Intel)
Link: http://lkml.kernel.org/r/20180918125151.31744-2-schwidef...@de.ibm.com
---
arch/Kconfig |3 +
include/asm-generic/tlb.h |9 +++
mm/mmu_gather.c | 107 +-
3 files changed, 70 insertions(+), 49 deletions(-)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -368,6 +368,9 @@ config HAVE_RCU_TABLE_NO_INVALIDATE
config HAVE_MMU_GATHER_PAGE_SIZE
bool
+config HAVE_MMU_GATHER_NO_GATHER
+ bool
+
config ARCH_HAVE_NMI_SAFE_CMPXCHG
bool
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -184,6 +184,7 @@ extern void tlb_remove_table(struct mmu_
#endif
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
/*
* If we can't allocate a page to make a big batch of page pointers
* to work on, then just handle a few from the on-stack structure.
@@ -208,6 +209,10 @@ struct mmu_gather_batch {
*/
#define MAX_GATHER_BATCH_COUNT (1UL/MAX_GATHER_BATCH)
+extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
+ int page_size);
+#endif
+
/*
* struct mmu_gather is an opaque type used by the mm code for passing around
* any data needed by arch specific code for tlb_remove_page.
@@ -254,6 +259,7 @@ struct mmu_gather {
unsigned intbatch_count;
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
struct mmu_gather_batch *active;
struct mmu_gather_batch local;
struct page *__pages[MMU_GATHER_BUNDLE];
@@ -261,6 +267,7 @@ struct mmu_gather {
#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
unsigned int page_size;
#endif
+#endif
};
void arch_tlb_gather_mmu(struct mmu_gather *tlb,
@@ -269,8 +276,6 @@ void tlb_flush_mmu(struct mmu_gather *tl
void arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force);
void tlb_flush_mmu_free(struct mmu_gather *tlb);
-extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
- int page_size);
static inline void __tlb_adjust_range(struct mmu_gather *tlb,
unsigned long address,
--- a/mm/mmu_gather.c
+++ b/mm/mmu_gather.c
@@ -13,6 +13,8 @@
#ifdef HAVE_GENERIC_MMU_GATHER
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
+
static bool tlb_next_batch(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch;
@@ -41,6 +43,56 @@ static bool tlb_next_batch(struct mmu_ga
return true;
}
+static void tlb_batch_pages_flush(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ for (batch = >local; batch && batch->nr; batch = batch->next) {
+ free_pages_and_swap_cache(batch->pages, batch->nr);
+ batch->nr = 0;
+ }
+ tlb->active = >local;
+}
+
+static void tlb_batch_list_free(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch, *next;
+
+ for (batch = tlb->local.next; batch; batch = next) {
+ next = batch->next;
+ free_pages((unsigned long)batch, 0);
+ }
+ tlb->local.next = NULL;
+}
+
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int
page_size)
+{
+ struct mmu_gather_batch *batch;
+
+ VM_BUG_ON(!tlb->end);
+
+#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
+ VM_WARN_ON(tlb->page_size != page_size);
+#endif
+
+ batch = tlb->active;
+ /*
+* Add the page and check if we are full. If so
+* force a flush.
+*/
+ batch->pages[batch->nr++] = page;
+ if (batch->nr == batch->max) {
+ if (!tlb_next_batch(tlb))
+ return true;
+ batch = tlb->active;
+ }
+ VM_BUG_ON_PAGE(batch->nr > batch->max, page);
+
+ return false;
+}
+
+#endif /* HAVE_MMU_GATHER_NO_GATHER */
+
void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
unsigned long start, unsigned long end)
{
@@ -48,12 +100,15 @@ void arch_tlb_gather_mmu(struct mmu_gath
/* Is it from 0 to ~0? */
tlb->fullmm = !(start | (end+1));
+
+#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
tlb->need_flush_all = 0;
tlb->local.next = NULL;
tlb->local.nr = 0;
tlb->local.max = ARRAY_SIZE(tlb->__pages);
tlb->active = >local;
