Merge branch 'writeback-workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into for-3.10/core

Tejun writes:

-----

This is the pull request for the earlier patchset[1] with the same
name.  It's only three patches (the first one was committed to
workqueue tree) but the merge strategy is a bit involved due to the
dependencies.

* Because the conversion needs features from wq/for-3.10,
  block/for-3.10/core is based on rc3, and wq/for-3.10 has conflicts
  with rc3, I pulled mainline (rc5) into wq/for-3.10 to prevent those
  workqueue conflicts from flaring up in block tree.

* Resolving the issue that Jan and Dave raised about debugging
  requires arch-wide changes.  The patchset is being worked on[2] but
  it'll have to go through -mm after these changes show up in -next,
  and not included in this pull request.

The three commits are located in the following git branch.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git writeback-workqueue

Pulling it into block/for-3.10/core produces a conflict in
drivers/md/raid5.c between the following two commits.

  e3620a3ad5 ("MD RAID5: Avoid accessing gendisk or queue structs when not available")
  2f6db2a707 ("raid5: use bio_reset()")

The conflict is trivial - one removes an "if ()" conditional while the
other removes "rbi->bi_next = NULL" right above it.  We just need to
remove both.  The merged branch is available at

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git block-test-merge

so that you can use it for verification.  The test merge commit has
proper merge description.

While these changes are a bit of pain to route, they make code simpler
and even have, while minute, measureable performance gain[3] even on a
workload which isn't particularly favorable to showing the benefits of
this conversion.

----

Fixed up the conflict.

Conflicts:
	drivers/md/raid5.c

Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 3 insertions, 31 deletions

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index ef6800ba2f03..91eeab81f52d 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -452,7 +452,7 @@ tracesys:
 	; using ERET won't work since next-PC has already committed
 	lr  r12, [efa]
 	GET_CURR_TASK_FIELD_PTR   TASK_THREAD, r11
-	st  r12, [r11, THREAD_FAULT_ADDR]
+	st  r12, [r11, THREAD_FAULT_ADDR]	; thread.fault_address
 
 	; PRE Sys Call Ptrace hook
 	mov r0, sp			; pt_regs needed
@@ -792,31 +792,6 @@ ARC_EXIT ret_from_fork
 
 ;################### Special Sys Call Wrappers ##########################
 
-; TBD: call do_fork directly from here
-ARC_ENTRY sys_fork_wrapper
-	SAVE_CALLEE_SAVED_USER
-	bl  @sys_fork
-	DISCARD_CALLEE_SAVED_USER
-
-	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz  tracesys_exit
-
-	b ret_from_system_call
-ARC_EXIT sys_fork_wrapper
-
-ARC_ENTRY sys_vfork_wrapper
-	SAVE_CALLEE_SAVED_USER
-	bl  @sys_vfork
-	DISCARD_CALLEE_SAVED_USER
-
-	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz  tracesys_exit
-
-	b ret_from_system_call
-ARC_EXIT sys_vfork_wrapper
-
 ARC_ENTRY sys_clone_wrapper
 	SAVE_CALLEE_SAVED_USER
 	bl  @sys_clone
diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c
index 2888ba5be47e..52bdc83c1495 100644
--- a/arch/arc/kernel/kgdb.c
+++ b/arch/arc/kernel/kgdb.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/kgdb.h>
+#include <linux/sched.h>
 #include <asm/disasm.h>
 #include <asm/cacheflush.h>
 
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index dc0f968dae0a..2d95ac07df7b 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -232,10 +232,8 @@ char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 
 	n += scnprintf(buf + n, len - n, "\n");
 
-#ifdef _ASM_GENERIC_UNISTD_H
 	n += scnprintf(buf + n, len - n,
-		       "OS ABI [v2]\t: asm-generic/{unistd,stat,fcntl}\n");
-#endif
+		       "OS ABI [v3]\t: no-legacy-syscalls\n");
 
 	return buf;
 }
diff --git a/arch/arc/kernel/sys.c b/arch/arc/kernel/sys.c
index f6bdd07583f3..9d6c1ca26af6 100644
--- a/arch/arc/kernel/sys.c
+++ b/arch/arc/kernel/sys.c
@@ -6,8 +6,6 @@
 #include <asm/syscalls.h>
 
 #define sys_clone	sys_clone_wrapper
-#define sys_fork	sys_fork_wrapper
-#define sys_vfork	sys_vfork_wrapper
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),