linux-kernel - Re: [PATCH 2/3] slub: Support for array operations

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Message-ID: <alpine.DEB.2.11.1502130948120.9442@gentwo.org>
Date:	Fri, 13 Feb 2015 09:49:24 -0600 (CST)
From:	Christoph Lameter <cl@...ux.com>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>
cc:	akpm@...uxfoundation.org, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, penberg@...nel.org, iamjoonsoo@....com,
	Jesper Dangaard Brouer <brouer@...hat.com>
Subject: Re: [PATCH 2/3] slub: Support for array operations

On Fri, 13 Feb 2015, Joonsoo Kim wrote:

> > +			*p++ = freelist;
> > +			freelist = get_freepointer(s, freelist);
> > +			allocated++;
> > +		}
>
> Fetching all objects with holding node lock could result in enomourous
> lock contention. How about getting free ojbect pointer without holding
> the node lock? We can temporarilly store all head of freelists in
> array p and can fetch each object pointer without holding node lock.


Could do that but lets first see if there is really an issue. The other
cpu sharing the same partial lists presumaly have cpu local objects to get
through first before they hit this lock.

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