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    <blockquote> <p>each time a <code>print</code> is involved the string is inserted into a linked list</p> </blockquote> <p>I don't really know if you meant <code>print</code> or <code>printk</code>. But if you're talking about <code>printk()</code>, You would need to allocate memory and you are in trouble because <code>printk()</code> may be called in an atomic context. Which leaves you the option to use a circular buffer (and thus, you should be tolerent to drop some strings because you might not have enough memory to save all the strings).</p> <blockquote> <p>Every X seconds I need to process the list and perform some operations on the strings before printing them.</p> </blockquote> <p>In that case, I would not even do a kernel thread: I would do the processing in <code>print()</code> if not too costly.</p> <p>Otherwise, I would create a new system call:</p> <ul> <li><code>sys_get_strings()</code> or something, that would dump the whole linked list into userspace (and remove entries from the list when copied).</li> </ul> <p>This way the whole behavior is controlled by userspace. You could create a deamon that would call the syscall every X seconds. You could also do all the costly processing in userspace.</p> <p>You could also create a new device says <code>/dev/print-on-screen</code>:</p> <ul> <li><code>dev_open</code> would allocate the memory, and <code>print()</code> would no longer be a no-op, but feed the data in the device pre-allocated memory (in case <code>print()</code> would be used in atomic context and all).</li> <li><code>dev_release</code> would throw everything out</li> <li><code>dev_read</code> would get you the strings</li> <li><code>dev_write</code> could do something on your print-on-screen system</li> </ul>
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    1. POKernel threads vs Timers
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    1. USNicolas Viennot
    1. USNicolas Viennot
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      1. VTUpMod
    1. CO+1 for giving me the idea to use a user space solution
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      1. USEmiliano
 

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