On Thu, 12 Apr 2007 11:38:30 -0600 Cameron Schaus <[EMAIL PROTECTED]> wrote:
> I am running the latest FC5-i686-smp kernel, 2.6.20, on a machine with > 8Gb of RAM, and 2 Xeon processors. The system has a 750Mb ramdisk, > and one process allocating and deallocating memory that is also > writing lots of files to the ramdisk. The process also reads and > writes from the network. After the process runs for a while, the > linux OOM killer starts killing processes, even though there is lots > of memory available. > > The system does not ordinarily use swap space, but I've added swap to > see if it makes a difference, but it only defers the problem. > > The OOM dump below shows that memory in the NORMAL_ZONE is exhausted, > but there is still plenty of memory (6Gb+) in the HighMem Zone. I can > provide .config and dmesg data if these would be helpful. > > Why is the OOM killer being invoked when there is still memory > available for use? > > java invoked oom-killer: gfp_mask=0xd0, order=0, oomkilladj=0 > java invoked oom-killer: gfp_mask=0xd0, order=0, oomkilladj=0 > [<c0455f84>] out_of_memory+0x69/0x191 > [<c0457460>] __alloc_pages+0x220/0x2aa > [<c046c80a>] cache_alloc_refill+0x26f/0x468 > [<c046ca76>] __kmalloc+0x73/0x7d > [<c05bb4ce>] __alloc_skb+0x49/0xf7 > [<c05e483d>] tcp_sendmsg+0x169/0xa04 > [<c05fd76d>] inet_sendmsg+0x3b/0x45 > [<c05b57d5>] sock_aio_write+0xf9/0x105 > [<c0455708>] generic_file_aio_read+0x173/0x1a3 > [<c046fd11>] do_sync_write+0xc7/0x10a > [<c04379fd>] autoremove_wake_function+0x0/0x35 > [<c05e413e>] tcp_ioctl+0x10a/0x115 > [<c05e4034>] tcp_ioctl+0x0/0x115 > [<c05fd406>] inet_ioctl+0x8d/0x91 > [<c0470564>] vfs_write+0xbc/0x154 > [<c0470b62>] sys_write+0x41/0x67 > [<c0403ef6>] sysenter_past_esp+0x5f/0x85 All of ZONE_NORMAL got used by ramdisk, and networking wants to allocate a page from ZONE_NORMAL. An oom-killing is the correct response, although probably not effective. ramdisk is a nasty thing - cannot you use ramfs or tmpfs? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/