On Sat, Feb 16, 2013 at 4:56 AM, Jimmy Pan dsp...@gmail.com wrote:
Hi,
I would like to write a driver for my usb mouse. It functions
normally with kernel driver, nonetheless, I want to study usb system.
When the kernel executes the probe function, what would happen if
there exists two
Hi,
we see this code in proc_pid_lookup:
tgid = name_to_int(dentry);
if (tgid == ~0U)
goto out;
In other words, if you ask for pid 0, it bails and doesn't return anything.
Are you sure that this is what it cjecks?
~0U is not 0 but -1;
for example, try:
On Sat, 2013-02-16 at 18:48 +0200, Kevin Wilson wrote:
Hi,
we see this code in proc_pid_lookup:
tgid = name_to_int(dentry);
if (tgid == ~0U)
goto out;
It is the error case when name can't be converted to integer i.e.
name is wrong.
In other words,
On Sat, 16 Feb 2013 18:48:52 +0200, Kevin Wilson said:
~0U is not 0 but -1;
-ENOCAFFEINE.
You'd think that after having done kernel-level C programming since the days
of SunOS 3.1.5 and BSD 4.2 I'd k know better. ;)
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On Fri, Feb 15, 2013 at 3:52 PM, buyitian bu...@live.cn wrote:
is it possible that printk cause deadlock? the path is as below:
1. taskA runs on CPU0, and run schedule to acqire the rq-lock.
2. taskA calls printk while holding rq-lock.
I began to get rusty on this...but, why do you grab run
