linux-kernel - Re: [PATCH v2 2/3] resource: Add release_mem_region

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.02.1304092315180.3916@chino.kir.corp.google.com>
Date:	Tue, 9 Apr 2013 23:16:25 -0700 (PDT)
From:	David Rientjes <rientjes@...gle.com>
To:	Toshi Kani <toshi.kani@...com>
cc:	akpm@...ux-foundation.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, linuxram@...ibm.com,
	guz.fnst@...fujitsu.com, tmac@...com,
	isimatu.yasuaki@...fujitsu.com, wency@...fujitsu.com,
	tangchen@...fujitsu.com, jiang.liu@...wei.com
Subject: Re: [PATCH v2 2/3] resource: Add release_mem_region_adjustable()

On Mon, 8 Apr 2013, Toshi Kani wrote:

> Added release_mem_region_adjustable(), which releases a requested
> region from a currently busy memory resource.  This interface
> adjusts the matched memory resource accordingly even if the
> requested region does not match exactly but still fits into.
> 
> This new interface is intended for memory hot-delete.  During
> bootup, memory resources are inserted from the boot descriptor
> table, such as EFI Memory Table and e820.  Each memory resource
> entry usually covers the whole contigous memory range.  Memory
> hot-delete request, on the other hand, may target to a particular
> range of memory resource, and its size can be much smaller than
> the whole contiguous memory.  Since the existing release interfaces
> like __release_region() require a requested region to be exactly
> matched to a resource entry, they do not allow a partial resource
> to be released.
> 
> There is no change to the existing interfaces since their restriction
> is valid for I/O resources.
> 
> Signed-off-by: Toshi Kani <toshi.kani@...com>
> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>

Should this emit a warning for attempting to free a non-existant region 
like __release_region() does?

I think it would be better to base this off my patch and surround it with 
#ifdef CONFIG_MEMORY_HOTREMOVE as suggested by Andrew.  There shouldn't be 
any conflicts.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/