The patch titled
Subject: uprobe: collapse THP pmd after removing all uprobes
has been added to the -mm tree. Its filename is
uprobe-collapse-thp-pmd-after-removing-all-uprobes.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/uprobe-collapse-thp-pmd-after-removing-all-uprobes.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/uprobe-collapse-thp-pmd-after-removing-all-uprobes.patch
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------------------------------------------------------
From: Song Liu <songliubraving@xxxxxx>
Subject: uprobe: collapse THP pmd after removing all uprobes
After all uprobes are removed from the huge page (with PTE pgtable), it is
possible to collapse the pmd and benefit from THP again. This patch does
the collapse by calling collapse_pte_mapped_thp().
Link: http://lkml.kernel.org/r/20190731183331.2565608-3-songliubraving@xxxxxx
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew.wilcox@xxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/events/uprobes.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/kernel/events/uprobes.c~uprobe-collapse-thp-pmd-after-removing-all-uprobes
+++ a/kernel/events/uprobes.c
@@ -26,6 +26,7 @@
#include <linux/percpu-rwsem.h>
#include <linux/task_work.h>
#include <linux/shmem_fs.h>
+#include <linux/khugepaged.h>
#include <linux/uprobes.h>
@@ -472,6 +473,7 @@ int uprobe_write_opcode(struct arch_upro
struct page *old_page, *new_page;
struct vm_area_struct *vma;
int ret, is_register, ref_ctr_updated = 0;
+ bool orig_page_huge = false;
is_register = is_swbp_insn(&opcode);
uprobe = container_of(auprobe, struct uprobe, arch);
@@ -529,6 +531,9 @@ retry:
/* let go new_page */
put_page(new_page);
new_page = NULL;
+
+ if (PageCompound(orig_page))
+ orig_page_huge = true;
}
put_page(orig_page);
}
@@ -547,6 +552,10 @@ put_old:
if (ret && is_register && ref_ctr_updated)
update_ref_ctr(uprobe, mm, -1);
+ /* try collapse pmd for compound page */
+ if (!ret && orig_page_huge)
+ collapse_pte_mapped_thp(mm, vaddr & HPAGE_PMD_MASK);
+
return ret;
}
_
Patches currently in -mm which might be from songliubraving@xxxxxx are
mm-move-memcmp_pages-and-pages_identical.patch
uprobe-use-original-page-when-all-uprobes-are-removed.patch
uprobe-use-original-page-when-all-uprobes-are-removed-v2.patch
mm-thp-introduce-foll_split_pmd.patch
mm-thp-introduce-foll_split_pmd-v11.patch
uprobe-use-foll_split_pmd-instead-of-foll_split.patch
khugepaged-enable-collapse-pmd-for-pte-mapped-thp.patch
uprobe-collapse-thp-pmd-after-removing-all-uprobes.patch
