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Date: Wed, 27 May 2026 14:28:26 +0300
From: Mike Rapoport <rppt@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>, Song Liu <song@kernel.org>,
	Yu Kuai <yukuai@fnnas.com>, Li Nan <linan122@huawei.com>,
	Xiao Ni <xiao@kernel.org>,
	David Laight <david.laight.linux@gmail.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-raid@vger.kernel.org
Subject: Re: [PATCH v2 2/2] lib/raid6: use kvmalloc() in raid6_select_algo()
Message-ID: <ahbVWp9L7ASV6zOL@kernel.org>
References: <20260526-lib-v2-0-ca3f0fc24b14@kernel.org>
 <20260526-lib-v2-2-ca3f0fc24b14@kernel.org>
 <20260526103424.0d884374dee8cbc4f9f17c3a@linux-foundation.org>
 <20260527063814.GA17042@lst.de>
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In-Reply-To: <20260527063814.GA17042@lst.de>

On Wed, May 27, 2026 at 08:38:14AM +0200, Christoph Hellwig wrote:
> On Tue, May 26, 2026 at 10:34:24AM -0700, Andrew Morton wrote:
> >  	/* prepare the buffer and fill it circularly with gfmul table */
> > -	disk_ptr = (char *)__get_free_pages(GFP_KERNEL, RAID6_TEST_DISKS_ORDER);
> > +	disk_ptr = kvmalloc(PAGE_SIZE * RAID6_TEST_DISKS, GFP_KERNEL);
> 
> This changes to vmalloc for no good reason.  It also doesn't use

TBH, I didn't look around and just presumed that order-3 allocation is a
good candidate for vmalloc(). 
But given this runs early on boot, there's no real reason for vmalloc().

> the _array version for overflow-safe multiplying (not that it matters
> much here..)
 
Can do _array if you'd like, no strong feelings here.

-- 
Sincerely yours,
Mike.