Messages in this thread | | | Date | Fri, 7 May 2004 12:26:50 -0700 (PDT) | From | Jon Smirl <> | Subject | Re: Is it possible to implement interrupt time printk's reliably? |
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--- Andrew Morton <akpm@osdl.org> wrote: > Jon Smirl <jonsmirl@yahoo.com> wrote: > > > > > If you're in process context you can use acquire_console_sem(), which will > > > serialise against printk. > > > > > > > Won't I deadlock if I have acquire_console_sem(), take an interrupt, and > then a > > printk is issued from the interrupt handelr? > > > > Nope. If printk finds the semaphore to be held it queues up the characters > and returns without printing them. The console_sem-holding process will > print the newly buffered characters before releasing the semaphore.
Is this solution sufficient for kernel developers wanting to use printk from interrupt handlers? I've gotten negative feedback from Linus when I suggested queuing them before.
===== Jon Smirl jonsmirl@yahoo.com
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