Re: System Tap help

On Thu, Apr 12, 2012 at 10:38 AM, V.Ravikumar wrote: > Hi all, > I'm probing sys_write system call using system tap to get modified file > name along with UID. > Here is code snippet. > > probe kernel.function ("vfs_write") > { > > filename = user_string($file->f_dentry->d_name->name) //

System Tap help

Hi all, I'm probing sys_write system call using system tap to get modified file name along with UID. Here is code snippet. probe kernel.function ("vfs_write") { filename = user_string($file->f_dentry->d_name->name) // for 2.6.18 kernel. printf ("%d %s\n",uid,filename) } I got sam

identity mapped paging

I am not clear about the use of identity mapped paging while paging is being enabled by the operating system. Also I don't understand at what point are the identity mappings no longer useful.According to this article http://geezer.osdevbrasil.net/osd/mem/index.htm#identity - "The page table entries

Re: IRQs and memory consistency

On 11.04.2012 10:35, Wink Saville wrote: > Do you have a read barrier in the IRQ? Ah, no I don't. > See "SMP BARRIER PAIRING" in: > > http://www.kernel.org/doc/Documentation/memory-barriers.txt [3] I saw that but only skimmed it. I'll let the mailing list know if it worked when I get a chance t

Re: IRQs and memory consistency

Do you have a read barrier in the IRQ? See "SMP BARRIER PAIRING" in: http://www.kernel.org/doc/Documentation/memory-barriers.txt -- Wink On Wed, Apr 11, 2012 at 4:59 AM, Christopher Harvey wrote: > On 10.04.2012 19:58, Wink Saville wrote: > > Sounds to me like there needs to be a flush of the

Re: kernel panic after VFS mount in FPGA board

On 2012-04-11 19:03:42 (+0530), pcuser p wrote: > I'm getting kernel panic after cramfs root file system is mounted,I am > expecting to enter login prompt after root file system is mounted. > > Kernel cmd line : mem=32M console=ttySAC0,115200 root=/dev/ram0 > rootfstype=cramfs init=/linuxrc initr

Re: TinyLinux project status

Hi Peter, 2012/4/10 Peter Teoh : > http://www.chibios.org/dokuwiki/doku.php?id=chibios:documents:requirements > > This is 2KiB RAM for recommended configuration. > > It is not Linux, but is based on RTOS. > Chibios looks interesting, thanks... > 2012/4/11 Peter Teoh >> >> minimum specs is availa

kernel panic after VFS mount in FPGA board

Hi, I'm doing kernel porting to arm926 based FPGA board,very minimal setup (uart + timer only) I'm getting kernel panic after cramfs root file system is mounted,I am expecting to enter login prompt after root file system is mounted. Below are the details #define PLAT_PHYS_OFFSET 0x8000

A problem about irq.

Hi, Recently, I am trying to test event channel on Xen. I write a module alloc an event channel and try to bind this channel to an irq handler. But every time I insmod the module, the kernel says that the action of binding fails. I use a function defined in drivers/xen/events.c like this: bind_e

Re: IRQs and memory consistency

On 10.04.2012 19:58, Wink Saville wrote: > Sounds to me like there needs to be a flush of the processor cache > by using memory barriers. I used a wmb(); right after I set the value I wanted. > I'm guessing that the IRQ is taken on a different thread and possibly > a different processor and the v

Re: IRQs and memory consistency

On 10.04.2012 22:18, Mulyadi Santosa wrote: > Hi > > On Wed, Apr 11, 2012 at 03:22, Christopher Harvey > wrote: >> The IRQ and the setting of the devid value happen fairly close to >> each other in time. (like less than a second, or closer) > > Hmmm, and how about the order? which one do you g

Migrating from SA_INTERRUPT to IRQF_DISABLED...

Hi, There is an old bug come up while migrating from 2.6.18 to 2.6.33The interrupts were generating correctly in 2.6.18 where the interrupt was registered using SA_INTERRUPT then while migrating to 2.6.33 this has been changed to IRQF_DISABLED this is the only change in migration... after doing