From: Minchan Kim <minchan@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
linux-api@vger.kernel.org, oleksandr@redhat.com,
Suren Baghdasaryan <surenb@google.com>,
Tim Murray <timmurray@google.com>,
Daniel Colascione <dancol@google.com>,
Sandeep Patil <sspatil@google.com>,
Sonny Rao <sonnyrao@google.com>,
Brian Geffon <bgeffon@google.com>, Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Shakeel Butt <shakeelb@google.com>,
John Dias <joaodias@google.com>,
Joel Fernandes <joel@joelfernandes.org>,
sj38.park@gmail.com, alexander.h.duyck@linux.intel.com,
Jann Horn <jannh@google.com>, Minchan Kim <minchan@kernel.org>
Subject: [PATCH v6 6/7] mm/madvise: employ mmget_still_valid for write lock
Date: Tue, 18 Feb 2020 17:44:32 -0800 [thread overview]
Message-ID: <20200219014433.88424-7-minchan@kernel.org> (raw)
In-Reply-To: <20200219014433.88424-1-minchan@kernel.org>
From: Oleksandr Natalenko <oleksandr@redhat.com>
Do the very same trick as we already do since 04f5866e41fb. KSM hints
will require locking mmap_sem for write since they modify vm_flags, so
for remote KSM hinting this additional check is needed.
Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
mm/madvise.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/madvise.c b/mm/madvise.c
index f6d9b9e66243..c55a18fe71f9 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1118,6 +1118,8 @@ int do_madvise(struct task_struct *target_task, struct mm_struct *mm,
if (write) {
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
+ if (current->mm != mm && !mmget_still_valid(mm))
+ goto skip_mm;
} else {
down_read(&mm->mmap_sem);
}
@@ -1169,6 +1171,7 @@ int do_madvise(struct task_struct *target_task, struct mm_struct *mm,
}
out:
blk_finish_plug(&plug);
+skip_mm:
if (write)
up_write(&mm->mmap_sem);
else
--
2.25.0.265.gbab2e86ba0-goog
next prev parent reply other threads:[~2020-02-19 1:44 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-19 1:44 [PATCH v6 0/7] introduce memory hinting API for external process Minchan Kim
2020-02-19 1:44 ` [PATCH v6 1/7] mm: pass task and mm to do_madvise Minchan Kim
2020-02-28 22:15 ` Suren Baghdasaryan
2020-02-19 1:44 ` [PATCH v6 2/7] mm: introduce external memory hinting API Minchan Kim
2020-02-20 19:13 ` kbuild test robot
2020-02-20 21:15 ` Minchan Kim
2020-02-20 21:21 ` Minchan Kim
2020-02-28 22:14 ` Suren Baghdasaryan
2020-03-02 19:18 ` Minchan Kim
2020-02-20 20:48 ` kbuild test robot
2020-02-19 1:44 ` [PATCH v6 3/7] mm: check fatal signal pending of target process Minchan Kim
2020-02-28 22:20 ` Suren Baghdasaryan
2020-02-19 1:44 ` [PATCH v6 4/7] pid: move pidfd_get_pid function to pid.c Minchan Kim
2020-02-28 22:22 ` Suren Baghdasaryan
2020-02-19 1:44 ` [PATCH v6 5/7] mm: support both pid and pidfd for process_madvise Minchan Kim
2020-02-28 22:41 ` Suren Baghdasaryan
2020-03-02 19:23 ` Minchan Kim
2020-03-02 19:38 ` Suren Baghdasaryan
2020-02-19 1:44 ` Minchan Kim [this message]
2020-02-28 23:19 ` [PATCH v6 6/7] mm/madvise: employ mmget_still_valid for write lock Suren Baghdasaryan
2020-03-02 7:33 ` Oleksandr Natalenko
2020-03-02 16:32 ` Suren Baghdasaryan
2020-02-19 1:44 ` [PATCH v6 7/7] mm/madvise: allow KSM hints for remote API Minchan Kim
2020-02-19 20:01 ` [PATCH v6 0/7] introduce memory hinting API for external process Andrew Morton
2020-02-19 21:05 ` Suren Baghdasaryan
2020-02-19 22:32 ` Minchan Kim
2020-02-19 22:51 ` Brian Geffon
2020-02-20 9:16 ` SeongJae Park
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