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Message-ID: <AANLkTil7YgW3eQZ-WQ3R8k2OowZt491boAuxjPe18oFy@mail.gmail.com> Date: Sun, 20 Jun 2010 00:06:52 +0530 From: Hari LKML <hari.lkml@...il.com> To: linux-kernel@...r.kernel.org Subject: Help in understanding the tasklets After reading some of the books and the codes here is my understanding about the tasklet_action function the function statrs some thing like this 1. If the tasklet is not running in another processor set the Bit TASKLET_STATE_RUN; <<if (tasklet_trylock(t))>> 2. clear the TASKLET_STATE_SCHED bit; <<if (!test_and_clear_bit(TASKLET_ STATE_SCHED, &t->state))>> 3. start the tasklet <<( t->func(t->data))>> Now when the tasklets function is running and the same interrupt is raised again but now handled by a different processor (in a SMP system) the tasklet is now scheduled in a different processor (because the TASKLET_STATE_SCHED is already cleared in step 2) and there are every chance of the same type of taklet running concurently in different processors thus braking the promise that same types of tasklets do not ever run simultaniously. I think i have misunderstood one or the other concept so please correct me and help me in understanding the Linux Kernel code more clearly. Please personally CC me all answers/comments posted to the list, to my mail id hari.lkml@...il.com. Hari -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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