From: Michel Lespinasse <walken@google.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Laurent Dufour <ldufour@linux.ibm.com>,
Vlastimil Babka <vbabka@suse.cz>,
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 v4 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER
Date: Mon, 20 Apr 2020 17:57:16 -0700 [thread overview]
Message-ID: <CANN689EDVibi-EO9+S01qLW7gSpzj3i7g9g=GiH5vGGKgFz2Qg@mail.gmail.com> (raw)
In-Reply-To: <20200420192806.GE5820@bombadil.infradead.org>
On Mon, Apr 20, 2020 at 12:28 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Tue, Apr 14, 2020 at 05:43:51PM -0700, Michel Lespinasse wrote:
> > @@ -90,7 +90,7 @@ static struct mm_struct tboot_mm = {
> ^^^^^^^^
> > .pgd = swapper_pg_dir,
> > .mm_users = ATOMIC_INIT(2),
> > .mm_count = ATOMIC_INIT(1),
> > - .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
> > + .mmap_sem = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem),
> ^^^^^^^
>
> Shome mishtake, shirley?
>
> I don't see that this particular patch buys us much. The name 'mmap_sem'
> is still used, and I appreciate we abstract away the type of the lock,
> but wouldn't this be better?
>
> - .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
> + MMAP_LOCK_INITIALIZER(tboot_mm),
Hmmm, that's significantly different from other initializers we have,
which may be a downside ? But other than that, it does seem completely
workable to me. Do you have a strong preference ?
--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
next prev parent reply other threads:[~2020-04-21 0:57 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 0:43 [PATCH v4 00/10] Add a new mmap locking API wrapping mmap_sem calls Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 01/10] mmap locking API: initial implementation as rwsem wrappers Michel Lespinasse
2020-04-20 19:48 ` Davidlohr Bueso
2020-04-21 0:48 ` Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 02/10] MMU notifier: use the new mmap locking API Michel Lespinasse
2020-04-20 19:51 ` Davidlohr Bueso
2020-04-15 0:43 ` [PATCH v4 03/10] DMA reservations: " Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 04/10] mmap locking API: use coccinelle to convert mmap_sem rwsem call sites Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 05/10] mmap locking API: convert mmap_sem call sites missed by coccinelle Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 06/10] mmap locking API: convert nested write lock sites Michel Lespinasse
2020-04-20 18:19 ` Daniel Jordan
2020-04-20 19:33 ` Matthew Wilcox
2020-04-21 0:51 ` Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 07/10] mmap locking API: add mmap_read_trylock_non_owner() Michel Lespinasse
2020-04-20 18:22 ` Daniel Jordan
2020-04-20 19:23 ` Matthew Wilcox
2020-04-21 0:55 ` Michel Lespinasse
2020-04-15 0:43 ` [PATCH v4 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER Michel Lespinasse
2020-04-20 18:23 ` Daniel Jordan
2020-04-20 19:28 ` Matthew Wilcox
2020-04-21 0:57 ` Michel Lespinasse [this message]
2020-04-15 0:43 ` [PATCH v4 09/10] mmap locking API: use lockdep_assert_held Michel Lespinasse
2020-04-21 2:35 ` Matthew Wilcox
2020-04-15 0:43 ` [PATCH v4 10/10] mmap locking API: rename mmap_sem to mmap_lock Michel Lespinasse
2020-04-20 18:28 ` Daniel Jordan
2020-04-21 5:33 ` kbuild test robot
2020-04-21 22:19 ` Michel Lespinasse
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