netdev - RE: [E1000-devel] [e100] Page allocation failure warning(?) in 2.6.36.3

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]

Date:	Thu, 13 Jan 2011 10:05:56 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Chris Rankin <rankincj@...oo.com>
Cc:	JesseBrandeburg <jesse.brandeburg@...el.com>,
	David Miller <davem@...emloft.net>,
	"e1000-devel@...ts.sourceforge.net" 
	<e1000-devel@...ts.sourceforge.net>,
	Tushar NDave <tushar.n.dave@...el.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	Jeffrey TKirsher <jeffrey.t.kirsher@...el.com>
Subject: RE: [E1000-devel] [e100] Page allocation failure warning(?) in
 2.6.36.3

Le jeudi 13 janvier 2011 à 01:00 -0800, Chris Rankin a écrit :
> --- On Thu, 13/1/11, Eric Dumazet <eric.dumazet@...il.com> wrote:
> > Problem is e100 allocates an order-6 page in DMA zone
> > (a 256 KB contigous area of ram)
> > 
> > This contigous area of ram is not available but just after
> > booting...
> 
> I suspected as much. Fortunately, this machine has no function apart from routing and can happily left untouched for extended periods of time.
> 
> > On such small router, I doubt you need more than 64 slots
> > in TX ring buffer.
> 
> But what would the effect of that change be to the interfaces' performance, please?

If you care of performance, dont unload/reload your driver all the time,
and dont use modules (this matter on old hardware because of TLB misses)

Anyway, the change ( 128 -> 64 ) is not needed, since the kernel message
is a warning only. The allocation is retried and apparently succeeds.

The __GFP_NOWARN should make the failed allocation not noticed at all.



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html