Dear Linux kernel code maintainer, some weeks ago in the course of a discussion on lkml (see http://www.uwsg.indiana.edu/hypermail/linux/kernel/0110.3/1553.html and follow-ups) linux kernels of the 2.4 series turned out to sometime lock up after 497.1 days of uptime, when the "jiffies" variable wraps back to zero. Checking the kernel code, I found a number of places where jiffies were compared in a way that seems to break when they wrap. For these, I made up patches to use the macros "time_before()" or "time_after()" that are supposed to handle wraparound correctly. For a small part of the patches, I believe you to be the relevant kernel code maintainer. Appended to this email you will find some lines explaining why I decided to mail or cc: you on this (an extract of the copyright notice or the MAINTAINERS file), followed by the patch itself. If I mailed you in error, please drop me a short note. I kindly ask you to approve the correctness of the patch, and pass it on to the relevant people for inclusion into the mainline kernel. Thanks, Tim Schmielau (tim@physik3.uni-rostock.de) MIPS P: Ralf Baechle M: ralf@gnu.org W: http://oss.sgi.com/mips/mips-howto.html L: linux-mips@oss.sgi.com S: Maintained --- linux-2.4.18-pre1/arch/mips/baget/vacserial.c Sun Sep 9 19:43:01 2001 +++ linux-2.4.18-pre1-jiffies64/arch/mips/baget/vacserial.c Fri Dec 28 14:57:14 2001 @@ -1785,7 +1785,7 @@ schedule_timeout(char_time); if (signal_pending(current)) break; - if (timeout && ((orig_jiffies + timeout) < jiffies)) + if (timeout && time_after(jiffies, orig_jiffies + timeout)) break; } current->state = TASK_RUNNING;
