This is a note to let you know that I have just added a patch titled
MIPS: Fix sched_getaffinity with MT FPAFF enabled
to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11-ckt27.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 0598aa815d20a76dcdecc274ca7d866867ba28a8 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@xxxxxxxxxxx>
Date: Sun, 19 Jul 2015 00:38:41 +0200
Subject: MIPS: Fix sched_getaffinity with MT FPAFF enabled
commit 1d62d737555e1378eb62a8bba26644f7d97139d2 upstream.
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.
Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/10740/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
arch/mips/kernel/mips-mt-fpaff.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/mips-mt-fpaff.c b/arch/mips/kernel/mips-mt-fpaff.c
index cb09862..ca16964 100644
--- 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_getaffinity(pid_t pid, unsigned int len,
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_getaffinity(pid_t pid, unsigned int len,
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);
--
1.9.1
