From: Ingo Molnar <mingo@kernel.org>
To: Aaron Thompson <dev@aaront.org>
Cc: Mike Rapoport <rppt@kernel.org>,
linux-mm@kvack.org, "H. Peter Anvin" <hpa@zytor.com>,
Alexander Potapenko <glider@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andy@infradead.org>,
Ard Biesheuvel <ardb@kernel.org>, Borislav Petkov <bp@alien8.de>,
Darren Hart <dvhart@infradead.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Ingo Molnar <mingo@redhat.com>, Marco Elver <elver@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
kasan-dev@googlegroups.com, linux-efi@vger.kernel.org,
linux-kernel@vger.kernel.org,
platform-driver-x86@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH v2 1/1] mm: Always release pages to the buddy allocator in memblock_free_late().
Date: Fri, 6 Jan 2023 04:12:49 +0100 [thread overview]
Message-ID: <Y7eRsWuu8jZgZtUt@gmail.com> (raw)
In-Reply-To: <0101018584d0b5a3-ea0e4d67-b00f-4254-8e1c-767fcafbec31-000000@us-west-2.amazonses.com>
* Aaron Thompson <dev@aaront.org> wrote:
>
> On 2023-01-05 02:48, Ingo Molnar wrote:
> > * Aaron Thompson <dev@aaront.org> wrote:
> >
> > > For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:
> > >
> > > v6.2-rc2:
> > > # grep -E 'Node|spanned|present|managed' /proc/zoneinfo
> > > Node 0, zone DMA
> > > spanned 4095
> > > present 3999
> > > managed 3840
> > > Node 0, zone DMA32
> > > spanned 246652
> > > present 245868
> > > managed 178867
> > >
> > > v6.2-rc2 + patch:
> > > # grep -E 'Node|spanned|present|managed' /proc/zoneinfo
> > > Node 0, zone DMA
> > > spanned 4095
> > > present 3999
> > > managed 3840
> > > Node 0, zone DMA32
> > > spanned 246652
> > > present 245868
> > > managed 222816 # +43,949 pages
> >
> > [ Note the annotation I added to the output - might be useful in the
> > changelog too. ]
> >
> > So this patch adds around +17% of RAM to this 1 GB virtual system? That
> > looks rather significant ...
> >
> > Thanks,
> >
> > Ingo
>
> It is significant, but I wouldn't describe it as being added. I would say
> that the system is currently losing 17% of RAM due to a bug, and this patch
> fixes that bug.
To the end-user gaining +17% [or +3%] extra usable RAM compared to what
they had before is what matters, and it's a big deal. :-)
Thanks,
Ingo
next prev parent reply other threads:[~2023-01-06 3:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-04 7:43 [PATCH 0/1] Pages not released from memblock to the buddy allocator Aaron Thompson
2023-01-05 1:43 ` David Rientjes
2023-01-05 4:17 ` [PATCH v2 " Aaron Thompson
[not found] ` <20230105041650.1485-1-dev@aaront.org>
2023-01-05 4:17 ` [PATCH v2 1/1] mm: Always release pages to the buddy allocator in memblock_free_late() Aaron Thompson
2023-01-30 7:40 ` Xu Yu
2023-01-05 10:48 ` Ingo Molnar
2023-01-06 2:02 ` Aaron Thompson
2023-01-06 3:12 ` Ingo Molnar [this message]
2023-01-30 7:47 ` Xu Yu
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