* Daniele Bellucci (bellucda@tiscali.it) wrote: > Hi list, > i'm a bit confused about the usage of spinlock_irq & spinlock_irq_save... > when do i need to save flags? ... and when i don't need to take care about flags? > spin_lock_irq/spin_unlock_irq will blindly disable irq then re-enable. this is fine if you _know_ irq is enabled. spin_lock_irqsave/spin_unlock_irqrestore allows you to save the current irq state, disable, then restore to original state. this is required when you _don't know_ if the irq was originally enabled. imagine: irq off -> spin_lock_irq/spin_unlock_irq -> oops, irq is now on thanks, -chris -- Linux Security Modules http://lsm.immunix.org http://lsm.bkbits.net -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
