From: Andy Lutomirski <luto@amacapital.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>, Ming Lin <mlin@kernel.org>,
Simon Ser <contact@emersion.fr>, Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>
Subject: Re: [PATCH 2/2] mm: adds NOSIGBUS extension for out-of-band shmem read
Date: Thu, 3 Jun 2021 12:24:56 -0700 [thread overview]
Message-ID: <1FD047D2-F5F3-4AC6-A4E4-DB8FB1568821@amacapital.net> (raw)
In-Reply-To: <CAHk-=wiNT0RhwHkLa14ts0PGQtVtDZbJniOQJ66wxzXz4Co2mw@mail.gmail.com>
> On Jun 3, 2021, at 12:14 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> On Thu, Jun 3, 2021 at 12:07 PM Hugh Dickins <hughd@google.com> wrote:
>>
>> But the point that we've arrived at, that I'm actually now fairly
>> happy with, is do *not* permit MAP_NOSIGBUS on MAP_SHARED mappings.
>
> Yeah, if that's sufficient, then that original patch should just work as-is.
>
> But there was some reason why people didn't like that patch
> originally, and I think it was literally about how it only worked on
> private mappings (the "we don't have a flag for it in the vm_flags"
> part was just a small detail.
>
> I guess that objection ended up changing over time.
>
>
I don’t understand the use case well enough to comment on whether MAP_PRIVATE is sufficient, but I’m with Hugh: if this feature is implemented for MAP_SHARED, it should be fully coherent.
next prev parent reply other threads:[~2021-06-03 19:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 23:22 [PATCH 0/2] mm: adds MAP_NOSIGBUS extension for " Ming Lin
2021-06-01 23:22 ` [PATCH 1/2] mm: make "vm_flags" be an u64 Ming Lin
2021-06-02 1:58 ` kernel test robot
2021-06-02 2:06 ` kernel test robot
2021-06-01 23:22 ` [PATCH 2/2] mm: adds NOSIGBUS extension for out-of-band shmem read Ming Lin
2021-06-02 0:16 ` Linus Torvalds
2021-06-02 1:06 ` Ming Lin
2021-06-02 2:13 ` Hugh Dickins
2021-06-02 2:02 ` kernel test robot
2021-06-02 3:49 ` Hugh Dickins
2021-06-03 0:05 ` Ming Lin
2021-06-03 0:46 ` Hugh Dickins
2021-06-03 18:25 ` Linus Torvalds
2021-06-03 19:07 ` Hugh Dickins
2021-06-03 19:12 ` Linus Torvalds
2021-06-03 19:15 ` Linus Torvalds
2021-06-03 19:24 ` Andy Lutomirski [this message]
2021-06-03 19:35 ` Simon Ser
2021-06-03 19:57 ` Ming Lin
2021-06-02 9:30 ` kernel test robot
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