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Date:   Tue, 12 Jul 2022 17:49:40 -0700 (PDT)
From:   Hugh Dickins <hughd@google.com>
To:     Nadav Amit <namit@vmware.com>
cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Hugh Dickins <hughd@google.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        X86 ML <x86@kernel.org>, Linux MM <linux-mm@kvack.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH v2] x86/mm/tlb: ignore f->new_tlb_gen when zero
In-Reply-To: <3DC1239B-FBE4-4EE0-B0D1-641B64697712@vmware.com>
Message-ID: <b6bcd4c5-2311-451a-4792-6c2bc450b6@google.com>
References: <20220710232837.3618-1-namit@vmware.com> <7672923F-D439-4867-9418-B1F44EE5CC44@vmware.com> <3DC1239B-FBE4-4EE0-B0D1-641B64697712@vmware.com>
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On Wed, 13 Jul 2022, Nadav Amit wrote:
> On Jul 11, 2022, at 10:39 AM, Nadav Amit <namit@vmware.com> wrote:
> > On Jul 10, 2022, at 4:28 PM, Nadav Amit <nadav.amit@gmail.com> wrote:
> >> From: Nadav Amit <namit@vmware.com>
> >> 
> >> Commit aa44284960d5 ("x86/mm/tlb: Avoid reading mm_tlb_gen when
> >> possible") introduced an optimization of skipping the flush if the TLB
> >> generation that is flushed (as provided in flush_tlb_info) was already
> >> flushed.
> > 
> > Dave,
> > 
> > Can you please review this patch today?
> > 
> > I feel bad (for a good reason) for breaking swap/migration.
> > 
> > Thanks,
> > Nadav
> 
> Ping?
> 
> As you know, this really must go into 5.19 or otherwise aa44284960d5
> reverted.

No, aa44284960d5 is not in 5.19-rc: it's in linux-next heading for 5.20.

Hugh