From: Vlastimil Babka <vbabka@suse.cz>
To: Michel Lespinasse <walken@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Laurent Dufour <ldufour@linux.ibm.com>,
Matthew Wilcox <willy@infradead.org>,
Liam Howlett <Liam.Howlett@oracle.com>,
Jerome Glisse <jglisse@redhat.com>,
Davidlohr Bueso <dave@stgolabs.net>,
David Rientjes <rientjes@google.com>,
Hugh Dickins <hughd@google.com>, Ying Han <yinghan@google.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
Daniel Jordan <daniel.m.jordan@oracle.com>
Subject: Re: [PATCH v5 06/10] mmap locking API: convert nested write lock sites
Date: Mon, 18 May 2020 12:32:03 +0200 [thread overview]
Message-ID: <6a23fcce-181b-01ad-4a83-ea24d07ac724@suse.cz> (raw)
In-Reply-To: <20200422001422.232330-7-walken@google.com>
On 4/22/20 2:14 AM, Michel Lespinasse wrote:
> Add API for nested write locks and convert the few call sites doing that.
>
> Signed-off-by: Michel Lespinasse <walken@google.com>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Perhaps we could even move SINGLE_DEPTH_NESTING into the wrapper? It's unlikely
there will be a new user with a different subclass?
> ---
> arch/um/include/asm/mmu_context.h | 3 ++-
> include/linux/mmap_lock.h | 5 +++++
> kernel/fork.c | 2 +-
> 3 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
> index 62262c5c7785..17ddd4edf875 100644
> --- a/arch/um/include/asm/mmu_context.h
> +++ b/arch/um/include/asm/mmu_context.h
> @@ -8,6 +8,7 @@
>
> #include <linux/sched.h>
> #include <linux/mm_types.h>
> +#include <linux/mmap_lock.h>
>
> #include <asm/mmu.h>
>
> @@ -47,7 +48,7 @@ static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
> * when the new ->mm is used for the first time.
> */
> __switch_mm(&new->context.id);
> - down_write_nested(&new->mmap_sem, 1);
> + mmap_write_lock_nested(new, SINGLE_DEPTH_NESTING);
> uml_setup_stubs(new);
> mmap_write_unlock(new);
> }
> diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
> index 97ac53b66052..a757cb30ae77 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
> @@ -11,6 +11,11 @@ static inline void mmap_write_lock(struct mm_struct *mm)
> down_write(&mm->mmap_sem);
> }
>
> +static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
> +{
> + down_write_nested(&mm->mmap_sem, subclass);
> +}
> +
> static inline int mmap_write_lock_killable(struct mm_struct *mm)
> {
> return down_write_killable(&mm->mmap_sem);
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 41d3f45c058e..a5d1d20ccba7 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -499,7 +499,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
> /*
> * Not linked in yet - no deadlock potential:
> */
> - down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
> + mmap_write_lock_nested(mm, SINGLE_DEPTH_NESTING);
>
> /* No ordering required: file already has been exposed. */
> RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
>
next prev parent reply other threads:[~2020-05-18 10:32 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-22 0:14 [PATCH v5 00/10] Add a new mmap locking API wrapping mmap_sem calls Michel Lespinasse
2020-04-22 0:14 ` [PATCH v5 01/10] mmap locking API: initial implementation as rwsem wrappers Michel Lespinasse
2020-05-18 9:28 ` Vlastimil Babka
2020-05-18 13:18 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 02/10] MMU notifier: use the new mmap locking API Michel Lespinasse
2020-05-18 9:28 ` Vlastimil Babka
2020-05-18 13:19 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 03/10] DMA reservations: " Michel Lespinasse
2020-05-18 9:30 ` Vlastimil Babka
2020-05-18 13:20 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 04/10] mmap locking API: use coccinelle to convert mmap_sem rwsem call sites Michel Lespinasse
2020-05-18 9:36 ` Vlastimil Babka
2020-05-18 13:21 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 05/10] mmap locking API: convert mmap_sem call sites missed by coccinelle Michel Lespinasse
2020-05-18 9:44 ` Vlastimil Babka
2020-05-18 13:23 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 06/10] mmap locking API: convert nested write lock sites Michel Lespinasse
2020-05-18 10:32 ` Vlastimil Babka [this message]
2020-05-19 12:54 ` Michel Lespinasse
2020-05-18 13:24 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 07/10] mmap locking API: add mmap_read_trylock_non_owner() Michel Lespinasse
2020-05-18 10:42 ` Vlastimil Babka
2020-04-22 0:14 ` [PATCH v5 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER Michel Lespinasse
2020-05-18 10:45 ` Vlastimil Babka
2020-05-19 12:56 ` Michel Lespinasse
2020-05-18 13:33 ` Laurent Dufour
2020-04-22 0:14 ` [PATCH v5 09/10] mmap locking API: add mmap_assert_locked Michel Lespinasse
2020-04-22 2:10 ` Michel Lespinasse
2020-04-22 2:18 ` Matthew Wilcox
2020-04-24 1:44 ` Michel Lespinasse
2020-04-22 0:14 ` [PATCH v5 10/10] mmap locking API: rename mmap_sem to mmap_lock Michel Lespinasse
2020-04-22 1:58 ` Matthew Wilcox
2020-04-22 22:54 ` Michel Lespinasse
2020-04-23 1:59 ` Matthew Wilcox
2020-04-24 1:26 ` Michel Lespinasse
2020-04-24 1:38 ` [PATCH v5.5 09/10] mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked() Michel Lespinasse
2020-05-18 11:01 ` Vlastimil Babka
2020-05-19 13:06 ` Michel Lespinasse
2020-04-24 1:39 ` [PATCH v5.5 10/10] mmap locking API: rename mmap_sem to mmap_lock Michel Lespinasse
2020-05-18 11:07 ` Vlastimil Babka
2020-05-19 13:12 ` Michel Lespinasse
2020-05-18 13:45 ` Laurent Dufour
2020-05-19 13:10 ` Michel Lespinasse
2020-05-19 13:20 ` Laurent Dufour
2020-05-19 15:32 ` Matthew Wilcox
2020-05-19 18:14 ` John Hubbard
2020-05-20 2:39 ` Michel Lespinasse
2020-05-20 7:32 ` John Hubbard
2020-05-20 8:02 ` Michel Lespinasse
2020-05-20 12:48 ` Jason Gunthorpe
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