Signed-off-by: Pedro Demarchi Gomes <pedrodemargomes@xxxxxxxxx>
---
include/linux/damon.h | 5 +-
mm/damon/Makefile | 2 +-
mm/damon/ops-common.c | 80 +++++
mm/damon/ops-common.h | 3 +
mm/damon/sysfs.c | 1 +
mm/damon/vaddr-writes.c | 735 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 824 insertions(+), 2 deletions(-)
create mode 100644 mm/damon/vaddr-writes.c
diff --git a/include/linux/damon.h b/include/linux/damon.h
index af525252b853..9a6027faa7a6 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -485,6 +485,7 @@ struct damos {
* enum damon_ops_id - Identifier for each monitoring operations implementation
*
* @DAMON_OPS_VADDR: Monitoring operations for virtual address spaces
+ * @DAMON_OPS_VADDR_WRITES: Monitoring only write operations for virtual address spaces
* @DAMON_OPS_FVADDR: Monitoring operations for only fixed ranges of virtual
* address spaces
* @DAMON_OPS_PADDR: Monitoring operations for the physical address space
@@ -492,6 +493,7 @@ struct damos {
*/
enum damon_ops_id {
DAMON_OPS_VADDR,
+ DAMON_OPS_VADDR_WRITES,
DAMON_OPS_FVADDR,
DAMON_OPS_PADDR,
NR_DAMON_OPS,
@@ -846,7 +848,8 @@ int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id);
static inline bool damon_target_has_pid(const struct damon_ctx *ctx)
{
- return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR;
+ return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_VADDR_WRITES
+ || ctx->ops.id == DAMON_OPS_FVADDR;
}
static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs)
diff --git a/mm/damon/Makefile b/mm/damon/Makefile
index 8b49012ba8c3..c3c8dce0b34a 100644
--- a/mm/damon/Makefile
+++ b/mm/damon/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-y := core.o
-obj-$(CONFIG_DAMON_VADDR) += ops-common.o vaddr.o
+obj-$(CONFIG_DAMON_VADDR) += ops-common.o vaddr.o vaddr-writes.o
obj-$(CONFIG_DAMON_PADDR) += ops-common.o paddr.o
obj-$(CONFIG_DAMON_SYSFS) += sysfs-common.o sysfs-schemes.o sysfs.o
obj-$(CONFIG_DAMON_RECLAIM) += modules-common.o reclaim.o
diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c
index d25d99cb5f2b..4a3cad303a60 100644
--- a/mm/damon/ops-common.c
+++ b/mm/damon/ops-common.c
@@ -9,6 +9,8 @@
#include <linux/page_idle.h>
#include <linux/pagemap.h>
#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
#include "ops-common.h"
@@ -67,6 +69,84 @@ void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
}
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+ struct folio *folio;
+
+ if (!pte_write(pte))
+ return false;
+ if (!is_cow_mapping(vma->vm_flags))
+ return false;
+ if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
+ return false;
+ folio = vm_normal_folio(vma, addr, pte);
+ if (!folio)
+ return false;
+ return folio_maybe_dma_pinned(folio);
+}
+
+static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmdp)
+{
+ pmd_t old, pmd = *pmdp;
+
+ if (pmd_present(pmd)) {
+ /* See comment in change_huge_pmd() */
+ old = pmdp_invalidate(vma, addr, pmdp);
+ if (pmd_dirty(old))
+ pmd = pmd_mkdirty(pmd);
+ if (pmd_young(old))
+ pmd = pmd_mkyoung(pmd);
+
+ pmd = pmd_wrprotect(pmd);
+ pmd = pmd_clear_soft_dirty(pmd);
+
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
+ pmd = pmd_swp_clear_soft_dirty(pmd);
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ }
+}
+
+static inline void clear_soft_dirty(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *pte)
+{
+ /*
+ * The soft-dirty tracker uses #PF-s to catch writes
+ * to pages, so write-protect the pte as well. See the
+ * Documentation/admin-guide/mm/soft-dirty.rst for full description
+ * of how soft-dirty works.
+ */
+ pte_t ptent = *pte;
+
+ if (pte_present(ptent)) {
+ pte_t old_pte;
+
+ if (pte_is_pinned(vma, addr, ptent))
+ return;
+ old_pte = ptep_modify_prot_start(vma, addr, pte);
+ ptent = pte_wrprotect(old_pte);
+ ptent = pte_clear_soft_dirty(ptent);
+ ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
+ } else if (is_swap_pte(ptent)) {
+ ptent = pte_swp_clear_soft_dirty(ptent);
+ set_pte_at(vma->vm_mm, addr, pte, ptent);
+ }
+}
