The patch titled
Subject: mm/hmm: unregister mmu_notifier when last HMM client quit
has been added to the -mm tree. Its filename is
mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Jérôme Glisse <jglisse@xxxxxxxxxx>
Subject: mm/hmm: unregister mmu_notifier when last HMM client quit
This code was lost in translation at one point. This properly call
mmu_notifier_unregister_no_release() once last user is gone. This fix the
zombie mm_struct as without this patch we do not drop the refcount we have
on it.
Link: http://lkml.kernel.org/r/20180320020038.3360-5-jglisse@xxxxxxxxxx
Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Evgeny Baskakov <ebaskakov@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Mark Hairgrove <mhairgrove@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Stephen Bates <sbates@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN mm/hmm.c~mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit mm/hmm.c
--- a/mm/hmm.c~mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit
+++ a/mm/hmm.c
@@ -244,10 +244,29 @@ EXPORT_SYMBOL(hmm_mirror_register);
void hmm_mirror_unregister(struct hmm_mirror *mirror)
{
struct hmm *hmm = mirror->hmm;
+ struct mm_struct *mm = NULL;
+ bool unregister = false;
down_write(&hmm->mirrors_sem);
list_del_init(&mirror->list);
+ unregister = list_empty(&hmm->mirrors);
up_write(&hmm->mirrors_sem);
+
+ if (!unregister)
+ return;
+
+ spin_lock(&hmm->mm->page_table_lock);
+ if (hmm->mm->hmm == hmm) {
+ mm = hmm->mm;
+ mm->hmm = NULL;
+ }
+ spin_unlock(&hmm->mm->page_table_lock);
+
+ if (mm == NULL)
+ return;
+
+ mmu_notifier_unregister_no_release(&hmm->mmu_notifier, mm);
+ kfree(hmm);
}
EXPORT_SYMBOL(hmm_mirror_unregister);
_
Patches currently in -mm which might be from jglisse@xxxxxxxxxx are
mm-hmm-fix-header-file-if-else-endif-maze-v2.patch
mm-hmm-unregister-mmu_notifier-when-last-hmm-client-quit.patch
mm-hmm-hmm_pfns_bad-was-accessing-wrong-struct.patch
mm-hmm-use-struct-for-hmm_vma_fault-hmm_vma_get_pfns-parameters-v2.patch
mm-hmm-remove-hmm_pfn_read-flag-and-ignore-peculiar-architecture-v2.patch
mm-hmm-use-uint64_t-for-hmm-pfn-instead-of-defining-hmm_pfn_t-to-ulong-v2.patch
mm-hmm-cleanup-special-vma-handling-vm_special.patch
mm-hmm-do-not-differentiate-between-empty-entry-or-missing-directory-v2.patch
mm-hmm-rename-hmm_pfn_device_unaddressable-to-hmm_pfn_device_private.patch
mm-hmm-move-hmm_pfns_clear-closer-to-where-it-is-use.patch
mm-hmm-factor-out-pte-and-pmd-handling-to-simplify-hmm_vma_walk_pmd.patch
mm-hmm-change-hmm_vma_fault-to-allow-write-fault-on-page-basis.patch
mm-hmm-use-device-driver-encoding-for-hmm-pfn-v2.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
