From mboxrd@z Thu Jan 1 00:00:00 1970 From: blaterblater@hotmail.com (Frank) Date: Sun, 28 Nov 2010 13:43:46 +0100 Subject: memory allocation errors on Marvell Kirkwood In-Reply-To: <20101128120857.GB23772@n2100.arm.linux.org.uk> References: <20101128120857.GB23772@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > -----Original Message----- > From: Russell King - ARM Linux [mailto:linux at arm.linux.org.uk] > Sent: Sunday, November 28, 2010 13:09 > To: Frank > Cc: linux-arm-kernel at lists.infradead.org > Subject: Re: memory allocation errors on Marvell Kirkwood > > On Sun, Nov 28, 2010 at 12:44:56PM +0100, Frank wrote: > > [323570.011580] swapper: page allocation failure. order:3, > mode:0x4020 > > Order 3. That's wanting 4K << 3, or 32K. > > > [323570.289988] Normal: 1057*4kB 3870*8kB 99*16kB 0*32kB 0*64kB > 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 36772kB > > And from this line, we see that we have no pages larger than 16K > available > in the system, despite having 36MB of free memory. IOW, your memory > has > become extremely fragmented. > > We don't guaranttee that this doesn't happen - in fact, we explicitly > tell > people that memory fragmentation _does_ happen and we do _not_ > guarantee > that allocations > order-0 will succeed. > > From the backtrace, I guess you're using a network interface with a MTU > larger than about 16K ? Physical network interface uses a MTU value of 1500. The ppp0 tunnel uses an MTU of 1400. Further note that I cannot reproduce this problem when transferring data with ftp directly over the physical network interface, nor when using cifs/smb over the ppp0 interface.