From: David Hildenbrand <david@redhat.com>
To: SeongJae Park <sj38.park@gmail.com>, akpm@linux-foundation.org
Cc: SeongJae Park <sjpark@amazon.de>,
Jonathan.Cameron@Huawei.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, amit@kernel.org,
benh@kernel.crashing.org, brendanhiggins@google.com,
corbet@lwn.net, dwmw@amazon.com, elver@google.com,
fan.du@intel.com, foersleo@amazon.de, greg@kroah.com,
gthelen@google.com, guoju.fgj@alibaba-inc.com,
jgowans@amazon.com, joe@perches.com, mgorman@suse.de,
mheyne@amazon.de, minchan@kernel.org, mingo@redhat.com,
namhyung@kernel.org, peterz@infradead.org, riel@surriel.com,
rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org,
shakeelb@google.com, shuah@kernel.org, sieberf@amazon.com,
snu@zelle79.org, vbabka@suse.cz, vdavydov.dev@gmail.com,
zgf574564920@gmail.com, linux-damon@amazon.com,
linux-mm@kvack.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v34 05/13] mm/damon: Implement primitives for the virtual memory address spaces
Date: Thu, 26 Aug 2021 16:09:23 +0200 [thread overview]
Message-ID: <358fa060-7702-d523-5169-f25a3de0c22e@redhat.com> (raw)
In-Reply-To: <20210716081449.22187-6-sj38.park@gmail.com>
> +static void damon_va_mkold(struct mm_struct *mm, unsigned long addr)
> +{
> + pte_t *pte = NULL;
> + pmd_t *pmd = NULL;
> + spinlock_t *ptl;
> +
I just stumbled over this, sorry for the dumb questions:
a) What do we know about that region we are messing with?
AFAIU, just like follow_pte() and follow_pfn(), follow_invalidate_pte()
should only be called on VM_IO and raw VM_PFNMAP mappings in general
(see the doc of follow_pte()). Do you even know that it's within a
single VMA and that there are no concurrent modifications?
b) Which locks are we holding?
I hope we're holding the mmap lock in read mode at least. Or how are you
making sure there are no concurrent modifications to page tables / VMA
layout ... ?
> + if (follow_invalidate_pte(mm, addr, NULL, &pte, &pmd, &ptl))
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-08-26 14:09 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 8:14 [PATCH v34 00/13] Introduce Data Access MONitor (DAMON) SeongJae Park
2021-07-16 8:14 ` [PATCH v34 01/13] mm: " SeongJae Park
2021-07-16 8:14 ` [PATCH v34 02/13] mm/damon/core: Implement region-based sampling SeongJae Park
2021-07-16 8:14 ` [PATCH v34 03/13] mm/damon: Adaptively adjust regions SeongJae Park
2021-07-16 8:14 ` [PATCH v34 04/13] mm/idle_page_tracking: Make PG_idle reusable SeongJae Park
2021-07-16 8:14 ` [PATCH v34 05/13] mm/damon: Implement primitives for the virtual memory address spaces SeongJae Park
2021-08-26 14:09 ` David Hildenbrand [this message]
2021-08-26 17:29 ` SeongJae Park
2021-08-26 21:42 ` David Hildenbrand
2021-08-27 11:06 ` SeongJae Park
2021-07-16 8:14 ` [PATCH v34 06/13] mm/damon: Add a tracepoint SeongJae Park
2021-07-16 8:14 ` [PATCH v34 07/13] mm/damon: Implement a debugfs-based user space interface SeongJae Park
2021-08-06 0:43 ` Andrew Morton
2021-08-06 11:46 ` SeongJae Park
2021-08-06 0:43 ` Andrew Morton
2021-08-06 11:47 ` SeongJae Park
2021-07-16 8:14 ` [PATCH v34 08/13] mm/damon/dbgfs: Export kdamond pid to the user space SeongJae Park
2021-07-16 8:14 ` [PATCH v34 09/13] mm/damon/dbgfs: Support multiple contexts SeongJae Park
2021-07-16 8:14 ` [PATCH v34 10/13] Documentation: Add documents for DAMON SeongJae Park
2021-07-16 8:14 ` [PATCH v34 11/13] mm/damon: Add kunit tests SeongJae Park
2021-07-16 8:14 ` [PATCH v34 12/13] mm/damon: Add user space selftests SeongJae Park
2021-07-16 8:14 ` [PATCH v34 13/13] MAINTAINERS: Update for DAMON SeongJae Park
2021-07-27 21:30 ` [PATCH v34 00/13] Introduce Data Access MONitor (DAMON) Shakeel Butt
2021-07-28 8:36 ` SeongJae Park
2021-08-02 8:24 ` SeongJae Park
2021-08-04 7:41 ` SeongJae Park
2021-08-06 0:03 ` Andrew Morton
2021-08-06 11:48 ` SeongJae Park
2021-08-09 14:07 ` SeongJae Park
2021-08-06 0:43 ` Andrew Morton
2021-08-06 11:48 ` SeongJae Park
2021-08-07 18:28 ` Andrew Morton
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