From: Ard Biesheuvel <ardb@kernel.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Michael Roth <michael.roth@amd.com>,
linux-efi@vger.kernel.org, x86@kernel.org,
linux-coco@lists.linux.dev, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Nikolay Borisov <nik.borisov@suse.com>,
stable@kernel.org, Tom Lendacky <thomas.lendacky@amd.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v2] efi/unaccepted: Fix off-by-one when checking for overlapping ranges
Date: Tue, 28 Nov 2023 12:50:01 +0100 [thread overview]
Message-ID: <CAMj1kXE65htEpXSL+h1X-zQ2RH4Oc193rac7=PBYMYJvEUBXNA@mail.gmail.com> (raw)
In-Reply-To: <9be0159e-1762-6c07-e6eb-a86f1c780118@suse.cz>
On Tue, 28 Nov 2023 at 12:25, Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 11/8/23 12:21, Ard Biesheuvel wrote:
> > On Fri, 3 Nov 2023 at 16:30, Vlastimil Babka <vbabka@suse.cz> wrote:
> >>
> >> On 11/3/23 16:13, Michael Roth wrote:
> >> > When a task needs to accept memory it will scan the accepting_list
> >> > to see if any ranges already being processed by other tasks overlap
> >> > with its range. Due to an off-by-one in the range comparisons, a task
> >> > might falsely determine that an overlapping range is being accepted,
> >> > leading to an unnecessary delay before it begins processing the range.
> >> >
> >> > Fix the off-by-one in the range comparison to prevent this and slightly
> >> > improve performance.
> >> >
> >> > Fixes: 50e782a86c98 ("efi/unaccepted: Fix soft lockups caused by parallel memory acceptance")
> >> > Link: https://lore.kernel.org/linux-mm/20231101004523.vseyi5bezgfaht5i@amd.com/T/#me2eceb9906fcae5fe958b3fe88e41f920f8335b6
> >> > Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> >> > Signed-off-by: Michael Roth <michael.roth@amd.com>
> >>
> >> More justification for introducing a common ranges_overlap() helper somewhere :)
> >>
> >> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> >>
> >
> > Thanks, I'll take this as a fix.
>
> Ping, can't see it in mainline nor -next?
>
Apologies - queued up now.
prev parent reply other threads:[~2023-11-28 11:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-03 15:13 [PATCH v2] efi/unaccepted: Fix off-by-one when checking for overlapping ranges Michael Roth
2023-11-03 15:30 ` Vlastimil Babka
2023-11-08 11:21 ` Ard Biesheuvel
2023-11-28 11:25 ` Vlastimil Babka
2023-11-28 11:50 ` Ard Biesheuvel [this message]
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