linux-kernel - Re: [PATCH] tcp: splice as many packets as possible at once

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: <20090115234408.GA1693@1wt.eu>
Date:	Fri, 16 Jan 2009 00:44:08 +0100
From:	Willy Tarreau <w@....eu>
To:	David Miller <davem@...emloft.net>
Cc:	herbert@...dor.apana.org.au, jarkao2@...il.com, zbr@...emap.net,
	dada1@...mosbay.com, ben@...s.com, mingo@...e.hu,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
	jens.axboe@...cle.com
Subject: Re: [PATCH] tcp: splice as many packets as possible at once

On Fri, Jan 16, 2009 at 12:42:55AM +0100, Willy Tarreau wrote:
> On Thu, Jan 15, 2009 at 03:34:49PM -0800, David Miller wrote:
> > From: Herbert Xu <herbert@...dor.apana.org.au>
> > Date: Fri, 16 Jan 2009 10:32:05 +1100
> > 
> > > On Thu, Jan 15, 2009 at 03:26:08PM -0800, David Miller wrote:
> > > > +static inline struct page *linear_to_page(struct page *page, unsigned int len,
> > > > +					  unsigned int offset)
> > > > +{
> > > > +	struct page *p = alloc_pages(GFP_KERNEL, 0);
> > > > +
> > > > +	if (!p)
> > > > +		return NULL;
> > > > +	memcpy(page_address(p) + offset, page_address(page) + offset, len);
> > > 
> > > This won't work very well if skb->head is longer than a page.
> > > 
> > > We'll need to divide it up into individual pages.
> > 
> > Oh yes the same bug I pointed out the other day.
> > 
> > But Willy can test this patch as-is,
> 
> Hey, nice work Dave. +3% performance from your previous patch
> (31.6 MB/s). It's going fine and stable here.

And BTW feel free to add my Tested-by if you want in case you merge
this fix.

Willy

--
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/