From 473ddd592c55c4fcafc27b61ee17905377d336b1 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 18 Jul 2015 22:49:39 +0000 Subject: kernel: fix sched_getaffinity on MIPS SMP systems (fixes enabling RPS/XPS in netifd with musl) Signed-off-by: Felix Fietkau SVN-Revision: 46420 --- ...-fix-sched_getaffinity-with-MT-FPAFF-enab.patch | 35 ++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 target/linux/generic/patches-4.1/130-MIPS-kernel-fix-sched_getaffinity-with-MT-FPAFF-enab.patch (limited to 'target/linux/generic/patches-4.1/130-MIPS-kernel-fix-sched_getaffinity-with-MT-FPAFF-enab.patch') diff --git a/target/linux/generic/patches-4.1/130-MIPS-kernel-fix-sched_getaffinity-with-MT-FPAFF-enab.patch b/target/linux/generic/patches-4.1/130-MIPS-kernel-fix-sched_getaffinity-with-MT-FPAFF-enab.patch new file mode 100644 index 0000000000..a7bfef347c --- /dev/null +++ b/target/linux/generic/patches-4.1/130-MIPS-kernel-fix-sched_getaffinity-with-MT-FPAFF-enab.patch @@ -0,0 +1,35 @@ +From: Felix Fietkau +Date: Sun, 19 Jul 2015 00:21:57 +0200 +Subject: [PATCH] MIPS: kernel: fix sched_getaffinity with MT FPAFF enabled + +p->thread.user_cpus_allowed is zero-initialized and is only filled on +the first sched_setaffinity call. + +To avoid adding overhead in the task initialization codepath, simply OR +the returned mask in sched_getaffinity with p->cpus_allowed. + +Cc: stable@vger.kernel.org +Signed-off-by: Felix Fietkau +--- + +--- a/arch/mips/kernel/mips-mt-fpaff.c ++++ b/arch/mips/kernel/mips-mt-fpaff.c +@@ -154,7 +154,7 @@ asmlinkage long mipsmt_sys_sched_getaffi + unsigned long __user *user_mask_ptr) + { + unsigned int real_len; +- cpumask_t mask; ++ cpumask_t allowed, mask; + int retval; + struct task_struct *p; + +@@ -173,7 +173,8 @@ asmlinkage long mipsmt_sys_sched_getaffi + if (retval) + goto out_unlock; + +- cpumask_and(&mask, &p->thread.user_cpus_allowed, cpu_possible_mask); ++ cpumask_or(&allowed, &p->thread.user_cpus_allowed, &p->cpus_allowed); ++ cpumask_and(&mask, &allowed, cpu_active_mask); + + out_unlock: + read_unlock(&tasklist_lock); -- cgit v1.2.3