From: Andi Kleen <ak@suse.de>
To: Matthew Wilcox <matthew@wil.cx>
Cc: "Martin K. Petersen" <mkp@wildopensource.com>,
Andi Kleen <ak@suse.de>,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org,
akpm@osdl.org, tony.luck@intel.com
Subject: Re: [PATCH] General purpose zeroed page slab
Date: Mon, 18 Oct 2004 21:06:59 +0000 [thread overview]
Message-ID: <20041018210658.GA8203@wotan.suse.de> (raw)
In-Reply-To: <20041018184210.GI16153@parcelfarce.linux.theplanet.co.uk>
> It's probably worth doing this with a static cachep in slab.c and only
> exposing a get_zeroed_page() / free_zeroed_page() interface, with the
> latter doing the memset to 0.
Putting a memset in there would be dumb because the mm cleanup already
zeroes the page tables.
My dirty bitmap proposal would make that faster however, same as
copy_page_range et.al.
> I disagree with Andi over the dumbness
> of zeroing the whole page. That makes it cache-hot, which is what you
> want from a page you allocate from slab.
It's already cache hot from the page table free and you only want one cache
line in it cache hot, not the whole page.
-Andi
WARNING: multiple messages have this Message-ID (diff)
From: Andi Kleen <ak@suse.de>
To: Matthew Wilcox <matthew@wil.cx>
Cc: "Martin K. Petersen" <mkp@wildopensource.com>,
Andi Kleen <ak@suse.de>,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org,
akpm@osdl.org, tony.luck@intel.com
Subject: Re: [PATCH] General purpose zeroed page slab
Date: Mon, 18 Oct 2004 23:06:59 +0200 [thread overview]
Message-ID: <20041018210658.GA8203@wotan.suse.de> (raw)
In-Reply-To: <20041018184210.GI16153@parcelfarce.linux.theplanet.co.uk>
> It's probably worth doing this with a static cachep in slab.c and only
> exposing a get_zeroed_page() / free_zeroed_page() interface, with the
> latter doing the memset to 0.
Putting a memset in there would be dumb because the mm cleanup already
zeroes the page tables.
My dirty bitmap proposal would make that faster however, same as
copy_page_range et.al.
> I disagree with Andi over the dumbness
> of zeroing the whole page. That makes it cache-hot, which is what you
> want from a page you allocate from slab.
It's already cache hot from the page table free and you only want one cache
line in it cache hot, not the whole page.
-Andi
next prev parent reply other threads:[~2004-10-18 21:06 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-14 16:50 [PATCH] General purpose zeroed page slab Martin K. Petersen
2004-10-14 16:50 ` Martin K. Petersen
2004-10-14 17:30 ` Brian Gerst
2004-10-14 17:30 ` Brian Gerst
2004-10-14 17:36 ` Matthew Wilcox
2004-10-14 17:36 ` Matthew Wilcox
2004-10-14 18:49 ` Dave Jones
2004-10-14 18:49 ` Dave Jones
2004-10-14 19:08 ` Denis Vlasenko
2004-10-14 19:08 ` Denis Vlasenko
2004-10-14 19:47 ` Matthew Wilcox
2004-10-14 19:47 ` Matthew Wilcox
2004-10-14 18:04 ` Andi Kleen
2004-10-14 18:04 ` Andi Kleen
2004-10-14 23:36 ` Adam Heath
2004-10-14 23:36 ` Adam Heath
2004-10-15 1:18 ` Andi Kleen
2004-10-15 1:18 ` Andi Kleen
2004-10-18 18:06 ` Martin K. Petersen
2004-10-18 18:06 ` Martin K. Petersen
2004-10-18 18:42 ` Matthew Wilcox
2004-10-18 18:42 ` Matthew Wilcox
2004-10-18 18:54 ` Martin K. Petersen
2004-10-18 18:54 ` Martin K. Petersen
2004-10-18 19:06 ` Andi Kleen
2004-10-18 19:06 ` Andi Kleen
2004-10-18 21:06 ` Andi Kleen [this message]
2004-10-18 21:06 ` Andi Kleen
2004-10-18 19:03 ` Luck, Tony
2004-10-18 19:03 ` Luck, Tony
2004-10-18 19:14 ` Matthew Wilcox
2004-10-18 19:14 ` Matthew Wilcox
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