From: Peter Zijlstra <peterz@infradead.org>
To: Nadav Amit <namit@vmware.com>
Cc: Jan Stancek <jstancek@redhat.com>,
Yang Shi <yang.shi@linux.alibaba.com>,
Will Deacon <will.deacon@arm.com>,
"minchan@kernel.org" <minchan@kernel.org>,
"mgorman@suse.de" <mgorman@suse.de>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [v2 PATCH] mm: mmu_gather: remove __tlb_reset_range() for force flush
Date: Tue, 14 May 2019 13:49:19 +0200 [thread overview]
Message-ID: <20190514114919.GO2589@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <9E536319-815D-4425-B4B6-8786D415442C@vmware.com>
On Tue, May 14, 2019 at 07:21:33AM +0000, Nadav Amit wrote:
> > On May 14, 2019, at 12:15 AM, Jan Stancek <jstancek@redhat.com> wrote:
> > Replacing fullmm with need_flush_all, brings the problem back / reproducer hangs.
>
> Maybe setting need_flush_all does not have the right effect, but setting
> fullmm and then calling __tlb_reset_range() when the PTEs were already
> zapped seems strange.
>
> fullmm is described as:
>
> /*
> * we are in the middle of an operation to clear
> * a full mm and can make some optimizations
> */
>
> And this not the case.
Correct; starting with fullmm would be wrong. For instance
tlb_start_vma() would do the wrong thing because it assumes the whole mm
is going away. But we're at tlb_finish_mmu() time and there the
difference doesn't matter anymore.
But yes, that's a wee abuse.
next prev parent reply other threads:[~2019-05-14 11:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <45c6096e-c3e0-4058-8669-75fbba415e07@email.android.com>
2019-05-14 7:15 ` [v2 PATCH] mm: mmu_gather: remove __tlb_reset_range() for force flush Jan Stancek
2019-05-14 7:21 ` Nadav Amit
2019-05-14 11:49 ` Peter Zijlstra [this message]
2019-05-14 11:43 ` Peter Zijlstra
2019-05-09 23:26 Yang Shi
2019-05-13 16:38 ` Will Deacon
2019-05-13 23:01 ` Yang Shi
2019-05-14 14:54 ` Will Deacon
2019-05-14 17:25 ` Yang Shi
2019-05-16 15:29 ` Jan Stancek
2019-05-20 2:59 ` Yang Shi
2019-05-14 11:52 ` Peter Zijlstra
2019-05-14 12:02 ` Will Deacon
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