linux-kernel - [PATCH V3 6/6] x86/intel_rdt: Re-enable pseudo-lock measurements

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Message-Id: <b0e79afd7832b5ebe3f2a2ebafc16dcf0b3f77dd.1536685533.git.reinette.chatre@intel.com>
Date:   Tue, 11 Sep 2018 10:14:37 -0700
From:   Reinette Chatre <reinette.chatre@...el.com>
To:     tglx@...utronix.de, fenghua.yu@...el.com, tony.luck@...el.com,
        peterz@...radead.org, mingo@...hat.com, acme@...nel.org
Cc:     gavin.hindman@...el.com, jithu.joseph@...el.com,
        dave.hansen@...el.com, hpa@...or.com, x86@...nel.org,
        linux-kernel@...r.kernel.org,
        Reinette Chatre <reinette.chatre@...el.com>
Subject: [PATCH V3 6/6] x86/intel_rdt: Re-enable pseudo-lock measurements

Commit 4a7a54a55e ("x86/intel_rdt: Disable PMU access") disabled
measurements of pseudo-locked regions because of incorrect usage
of the performance monitoring hardware.

Cache pseudo-locking measurements are now done correctly with the
in-kernel perf API and its use can be re-enabled at this time.

The adjustment to the in-kernel perf API also separated the L2 and L3
measurements that can be triggered separately from user space. The
re-enabling of the measurements is thus not a simple revert of the
original disable in order to accommodate the additional parameter
possible.

Signed-off-by: Reinette Chatre <reinette.chatre@...el.com>
---
 arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
index 5a294fe080d7..e2bd212f382f 100644
--- a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
+++ b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
@@ -1226,7 +1226,7 @@ static ssize_t pseudo_lock_measure_trigger(struct file *file,
 	buf[buf_size] = '\0';
 	ret = kstrtoint(buf, 10, &sel);
 	if (ret == 0) {
-		if (sel != 1)
+		if (sel != 1 && sel != 2 && sel != 3)
 			return -EINVAL;
 		ret = debugfs_file_get(file->f_path.dentry);
 		if (ret)
-- 
2.17.0