From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>,
Suren Baghdasaryan <surenb@google.com>,
akpm@linux-foundation.org, liam.howlett@oracle.com,
mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org,
mjguzik@gmail.com, oliver.sang@intel.com,
mgorman@techsingularity.net, david@redhat.com, peterx@redhat.com,
oleg@redhat.com, dave@stgolabs.net, paulmck@kernel.org,
brauner@kernel.org, dhowells@redhat.com, hdanton@sina.com,
hughd@google.com, minchan@google.com, jannh@google.com,
souravpanda@google.com, pasha.tatashin@soleen.com,
corbet@lwn.net, linux-doc@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v4 0/5] move per-vma lock into vm_area_struct
Date: Fri, 22 Nov 2024 11:56:48 +0000 [thread overview]
Message-ID: <e71408ff-b088-48e6-8b18-bb846a60cc1e@lucifer.local> (raw)
In-Reply-To: <Zz6UTvERgg9ubRu4@casper.infradead.org>
On Thu, Nov 21, 2024 at 02:00:46AM +0000, Matthew Wilcox wrote:
> On Wed, Nov 20, 2024 at 02:10:44PM -0800, Shakeel Butt wrote:
> > If 'struct vm_area_struct' is prone to performance issues due to
> > cacheline misalignments then we should do something about the
> > __randomize_layout tag for it. I imagine we can identify the fields
> > which might be performance critical to be on same cacheline or different
> > cacheline due to false sharing then we can divide the fields into
> > different cacheline groups and fields can be __randomize_layout within
> > the group. WDYT?
>
> Pretty sure the people who think security is more important than
> performance are the only ones who randomize structs.
I agree that I don't think we need concern ourselves with users of this
setting for precisely this reason.
I wouldn't want supporting this to cause difficulty for users who do not
enable this when those who do aren't really concerned about the perf issues
as Matthew says.
next prev parent reply other threads:[~2024-11-22 11:57 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-20 0:08 Suren Baghdasaryan
2024-11-20 0:08 ` [PATCH v4 1/5] mm: introduce vma_start_read_locked{_nested} helpers Suren Baghdasaryan
2024-11-20 22:11 ` Shakeel Butt
2024-11-20 0:08 ` [PATCH v4 2/5] mm: move per-vma lock into vm_area_struct Suren Baghdasaryan
2024-11-20 23:32 ` Shakeel Butt
2024-11-20 23:44 ` Suren Baghdasaryan
2024-11-21 0:04 ` Shakeel Butt
2024-11-21 0:33 ` Suren Baghdasaryan
2024-11-21 7:01 ` Shakeel Butt
2024-11-21 17:05 ` Suren Baghdasaryan
2024-11-21 18:25 ` Shakeel Butt
2024-11-20 0:08 ` [PATCH v4 3/5] mm: mark vma as detached until it's added into vma tree Suren Baghdasaryan
2024-11-21 0:13 ` Shakeel Butt
2024-11-22 16:46 ` Lorenzo Stoakes
2024-11-22 17:47 ` Suren Baghdasaryan
2024-11-20 0:08 ` [PATCH v4 4/5] mm: make vma cache SLAB_TYPESAFE_BY_RCU Suren Baghdasaryan
2024-11-20 4:36 ` Matthew Wilcox
2024-11-20 6:37 ` Suren Baghdasaryan
2024-11-22 22:43 ` Suren Baghdasaryan
2024-11-20 10:16 ` Vlastimil Babka
2024-11-20 15:54 ` Suren Baghdasaryan
2024-11-20 0:08 ` [PATCH v4 5/5] docs/mm: document latest changes to vm_lock Suren Baghdasaryan
2024-11-20 22:10 ` [PATCH v4 0/5] move per-vma lock into vm_area_struct Shakeel Butt
2024-11-20 23:52 ` Suren Baghdasaryan
2024-11-21 2:00 ` Matthew Wilcox
2024-11-22 11:56 ` Lorenzo Stoakes [this message]
2024-11-22 15:06 ` Suren Baghdasaryan
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