Messages in this thread Patch in this message | | | Subject | Bug in sys_sched_yield | From | "Hubertus Franke" <> | Date | Wed, 11 Apr 2001 15:31:37 -0400 |
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In the recent optimizations to sys_sched_yield a bug was introduced. In the current implementation of sys_sched_yield() the aligned_data and idle_tasks are indexed by logical cpu-#.
They should however be indexed by physical cpu-#. Since logical==physical on the x86 platform, it doesn't matter there, for other platforms where this is not true it will matter. Below is the fix.
diff -uwrbBN linux-2.4.3/kernel/sched.c linux-2.4.3-fix/kernel/sched.c --- linux-2.4.3/kernel/sched.c Thu Mar 22 12:20:45 2001 +++ linux-2.4.3-fix/kernel/sched.c Wed Apr 11 11:27:16 2001 @@ -1024,9 +1024,11 @@ int i;
// Substract non-idle processes running on other CPUs. - for (i = 0; i < smp_num_cpus; i++) - if (aligned_data[i].schedule_data.curr != idle_task(i)) + for (i = 0; i < smp_num_cpus; i++) { + int cpu = cpu_logical_map(i); + if (aligned_data[cpu].schedule_data.curr != idle_task(cpu)) nr_pending--; + } #else // on UP this process is on the runqueue as well nr_pending--; Hubertus Franke Enterprise Linux Group (Mgr), Linux Technology Center (Member Scalability)
email: frankeh@us.ibm.com (w) 914-945-2003 (fax) 914-945-4425 TL: 862-2003
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