Commit 6ab88863 authored by Stephen Rothwell's avatar Stephen Rothwell Committed by Ingo Molnar
Browse files

perf: hw_breakpoints: Fix percpu namespace clash 



Today's linux-next build failed with:

  kernel/hw_breakpoint.c:86: error: 'task_bp_pinned' redeclared as different kind of symbol
  ...

Caused by commit dd17c8f7 ("percpu:
remove per_cpu__ prefix") from the percpu tree interacting with
commit 56053170 ("hw-breakpoints:
Fix task-bound breakpoint slot allocation") from the tip tree.

Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20091208182515.bb6dda4a.sfr@canb.auug.org.au>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2ff6cfd7

kernel/hw_breakpoint.c

+7 −7
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ 
static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned);



/* Number of pinned task breakpoints in a cpu */

static DEFINE_PER_CPU(unsigned int, task_bp_pinned[HBP_NUM]);

static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[HBP_NUM]);



/* Number of non-pinned cpu/task breakpoints in a cpu */

static DEFINE_PER_CPU(unsigned int, nr_bp_flexible);
@@ -73,7 +73,7 @@ static DEFINE_MUTEX(nr_bp_mutex); 
static unsigned int max_task_bp_pinned(int cpu)

{

	int i;

	unsigned int *tsk_pinned = per_cpu(task_bp_pinned, cpu);

	unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned, cpu);



	for (i = HBP_NUM -1; i >= 0; i--) {

		if (tsk_pinned[i] > 0)
@@ -162,7 +162,7 @@ static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable) 


	count = task_bp_pinned(tsk);



	tsk_pinned = per_cpu(task_bp_pinned, cpu);

	tsk_pinned = per_cpu(nr_task_bp_pinned, cpu);

	if (enable) {

		tsk_pinned[count]++;

		if (count > 0)
@@ -209,7 +209,7 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) 
 *   - If attached to a single cpu, check:

 *

 *       (per_cpu(nr_bp_flexible, cpu) || (per_cpu(nr_cpu_bp_pinned, cpu)

 *           + max(per_cpu(task_bp_pinned, cpu)))) < HBP_NUM

 *           + max(per_cpu(nr_task_bp_pinned, cpu)))) < HBP_NUM

 *

 *       -> If there are already non-pinned counters in this cpu, it means

 *          there is already a free slot for them.
@@ -220,7 +220,7 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) 
 *   - If attached to every cpus, check:

 *

 *       (per_cpu(nr_bp_flexible, *) || (max(per_cpu(nr_cpu_bp_pinned, *))

 *           + max(per_cpu(task_bp_pinned, *)))) < HBP_NUM

 *           + max(per_cpu(nr_task_bp_pinned, *)))) < HBP_NUM

 *

 *       -> This is roughly the same, except we check the number of per cpu

 *          bp for every cpu and we keep the max one. Same for the per tasks
@@ -232,7 +232,7 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) 
 *   - If attached to a single cpu, check:

 *

 *       ((per_cpu(nr_bp_flexible, cpu) > 1) + per_cpu(nr_cpu_bp_pinned, cpu)

 *            + max(per_cpu(task_bp_pinned, cpu))) < HBP_NUM

 *            + max(per_cpu(nr_task_bp_pinned, cpu))) < HBP_NUM

 *

 *       -> Same checks as before. But now the nr_bp_flexible, if any, must keep

 *          one register at least (or they will never be fed).
@@ -240,7 +240,7 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) 
 *   - If attached to every cpus, check:

 *

 *       ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *))

 *            + max(per_cpu(task_bp_pinned, *))) < HBP_NUM

 *            + max(per_cpu(nr_task_bp_pinned, *))) < HBP_NUM

 */

int reserve_bp_slot(struct perf_event *bp)

{

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