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From: Matthew Wilcox <willy@infradead.org>
To: Baoquan He <bhe@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	akpm@linux-foundation.org, stephen.s.brennan@oracle.com,
	urezki@gmail.com, hch@infradead.org
Subject: Re: [PATCH RFC 3/3] mm/vmalloc.c: allow vread() to read out vm_map_ram areas
Date: Fri, 18 Nov 2022 08:01:50 +0000	[thread overview]
Message-ID: <Y3c77o95A9vKQ745@casper.infradead.org> (raw)
In-Reply-To: <20221109033535.269229-4-bhe@redhat.com>

On Wed, Nov 09, 2022 at 11:35:34AM +0800, Baoquan He wrote:
> Currently, vread() can read out vmalloc areas which is associated with
> a vm_struct. While this doesn't work for areas created by vm_map_ram()
> interface because it doesn't allocate a vm_struct. Then in vread(),
> these areas will be skipped.
> 
> Here, add a new function vb_vread() to read out areas managed by
> vmap_block specifically. Then recognize vm_map_ram areas via vmap->flags
> and handle  them respectively.

i don't understand how this deals with the original problem identified,
that the vread() can race with an unmap.


  parent reply	other threads:[~2022-11-18  8:01 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-09  3:35 [PATCH RFC 0/3] mm/vmalloc.c: allow vread() to read out vm_map_ram areas Baoquan He
2022-11-09  3:35 ` [PATCH RFC 1/3] mm/vmalloc.c: add used_map into vmap_block to track space of vmap_block Baoquan He
2022-11-09  3:35 ` [PATCH RFC 2/3] mm/vmalloc.c: add flags to mark vm_map_ram area Baoquan He
2022-11-09  3:35 ` [PATCH RFC 3/3] mm/vmalloc.c: allow vread() to read out vm_map_ram areas Baoquan He
2022-11-10  0:59   ` Stephen Brennan
2022-11-10 10:23     ` Baoquan He
2022-11-10 18:48       ` Stephen Brennan
2022-11-14 10:06         ` Baoquan He
2022-11-18  8:01   ` Matthew Wilcox [this message]
2022-11-23  3:38     ` Baoquan He
2022-11-23 13:24       ` Matthew Wilcox
2022-11-24  9:52         ` Baoquan He
2022-11-30 13:06           ` Uladzislau Rezki
2022-12-01  4:46             ` Baoquan He

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