mm/migration: add trace events for THP migrations

Patch series "mm/migration: Add trace events", v3.

This adds trace events for all migration scenarios including base page,
THP and HugeTLB.

This patch (of 3):

This adds two trace events for PMD based THP migration without split.
These events closely follow the implementation details like setting and
removing of PMD migration entries, which are essential operations for THP
migration.  This moves CREATE_TRACE_POINTS into generic THP from powerpc
for these new trace events to be available on other platforms as well.

Link: https://lkml.kernel.org/r/1643368182-9588-1-git-send-email-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/1643368182-9588-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/powerpc/mm/book3s64/trace.c b/arch/powerpc/mm/book3s64/trace.c
index b86e7b90625713b8db7d512d61d6242555c2dabf..ccd64b5e6cac70aca7dc5d1d0c2eaca1e0247fb9 100644 (file)
--- a/arch/powerpc/mm/book3s64/trace.c
+++ b/arch/powerpc/mm/book3s64/trace.c
@@ -3,6 +3,5 @@
  * This file is for defining trace points and trace related helpers.
  */
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define CREATE_TRACE_POINTS
 #include <trace/events/thp.h>
 #endif

diff --git a/include/trace/events/thp.h b/include/trace/events/thp.h
index ca3f2767828a64d54fb42cc753a92bd860d0c336..202b3e3e67ff2a16d9788d8d2040c0614d2f9be2 100644 (file)
--- a/include/trace/events/thp.h
+++ b/include/trace/events/thp.h
@@ -48,6 +48,33 @@ TRACE_EVENT(hugepage_update,
            TP_printk("hugepage update at addr 0x%lx and pte = 0x%lx clr = 0x%lx, set = 0x%lx", __entry->addr, __entry->pte, __entry->clr, __entry->set)
 );
 
+DECLARE_EVENT_CLASS(migration_pmd,
+
+               TP_PROTO(unsigned long addr, unsigned long pmd),
+
+               TP_ARGS(addr, pmd),
+
+               TP_STRUCT__entry(
+                       __field(unsigned long, addr)
+                       __field(unsigned long, pmd)
+               ),
+
+               TP_fast_assign(
+                       __entry->addr = addr;
+                       __entry->pmd = pmd;
+               ),
+               TP_printk("addr=%lx, pmd=%lx", __entry->addr, __entry->pmd)
+);
+
+DEFINE_EVENT(migration_pmd, set_migration_pmd,
+       TP_PROTO(unsigned long addr, unsigned long pmd),
+       TP_ARGS(addr, pmd)
+);
+
+DEFINE_EVENT(migration_pmd, remove_migration_pmd,
+       TP_PROTO(unsigned long addr, unsigned long pmd),
+       TP_ARGS(addr, pmd)
+);
 #endif /* _TRACE_THP_H */
 
 /* This part must be outside protection */

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 005fab2f3b73a56966e2ab9c5e81701b402746be..035aa204ab8d5dc4e615fd322e9a79dd46726dad 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -40,6 +40,9 @@
 #include <asm/pgalloc.h>
 #include "internal.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/thp.h>
+
 /*
  * By default, transparent hugepage support is disabled in order to avoid
  * risking an increased memory footprint for applications that are not
@@ -3131,6 +3134,7 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
        set_pmd_at(mm, address, pvmw->pmd, pmdswp);
        page_remove_rmap(page, vma, true);
        put_page(page);
+       trace_set_migration_pmd(address, pmd_val(pmdswp));
 }
 
 void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new)
@@ -3163,5 +3167,6 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new)
 
        /* No need to invalidate - it was non-present before */
        update_mmu_cache_pmd(vma, address, pvmw->pmd);
+       trace_remove_migration_pmd(address, pmd_val(pmde));
 }
 #endif