Hi all, I DO know you guys must be very busy always, so I am sorry to disturb you. I please ask you to let me know the reason why the changes made in co_timer_ack() function on Mips kernel v2.6.23.1. Because I got a problem on kernel v2.6.10 that the timer interrupt had ignored rarely and it causes no updates for "jiffies" for a while (approx. 4min on my board). And I found the change - a part of your excellent works - on v2.6.23.1 for co_timer_ack() function in time.c. v2.6.10 kernel: /* Check to see if we have missed any timer interrupts. */ count = read_c0_count(); if ((count - expirelo) < 0x7fffffff) { /* missed_timer_count++; */ expirelo = count + cycles_per_jiffy; write_c0_compare(expirelo); } v2.6.23.1 kernel: /* Check to see if we have missed any timer interrupts. */ while (((count = read_c0_count()) - expirelo) < 0x7fffffff) { /* missed_timer_count++; */ expirelo = count + cycles_per_jiffy; write_c0_compare(expirelo); } So, I plase ask you a couple of my questions - 1) What kind of phenomena did this change cause ? 2) What is the defect that this part of codes in v2.6.10 kernel has ? Please let me know. Thanks, Best regards, tnishioka