[tip:,x86/mm] mm: Expose untagging mask in /proc/$PID/status
Commit Message
The following commit has been merged into the x86/mm branch of tip:
Commit-ID: f7d304343b9d2456ffba23b99d2345408251ea45
Gitweb: https://git.kernel.org/tip/f7d304343b9d2456ffba23b99d2345408251ea45
Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
AuthorDate: Sun, 12 Mar 2023 14:26:04 +03:00
Committer: Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Thu, 16 Mar 2023 13:08:40 -07:00
mm: Expose untagging mask in /proc/$PID/status
Add a line in /proc/$PID/status to report untag_mask. It can be
used to find out LAM status of the process from the outside. It is
useful for debuggers.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-10-kirill.shutemov%40linux.intel.com
---
arch/arm64/include/asm/mmu_context.h | 6 ++++++
arch/sparc/include/asm/mmu_context_64.h | 6 ++++++
arch/x86/include/asm/mmu_context.h | 6 ++++++
fs/proc/array.c | 7 +++++++
include/linux/mmu_context.h | 7 +++++++
5 files changed, 32 insertions(+)
@@ -288,6 +288,12 @@ void post_ttbr_update_workaround(void);
unsigned long arm64_mm_context_get(struct mm_struct *mm);
void arm64_mm_context_put(struct mm_struct *mm);
+#define mm_untag_mask mm_untag_mask
+static inline unsigned long mm_untag_mask(struct mm_struct *mm)
+{
+ return -1UL >> 8;
+}
+
#include <asm-generic/mmu_context.h>
#endif /* !__ASSEMBLY__ */
@@ -185,6 +185,12 @@ static inline void finish_arch_post_lock_switch(void)
}
}
+#define mm_untag_mask mm_untag_mask
+static inline unsigned long mm_untag_mask(struct mm_struct *mm)
+{
+ return -1UL >> adi_nbits();
+}
+
#include <asm-generic/mmu_context.h>
#endif /* !(__ASSEMBLY__) */
@@ -104,6 +104,12 @@ static inline void dup_lam(struct mm_struct *oldmm, struct mm_struct *mm)
mm->context.untag_mask = oldmm->context.untag_mask;
}
+#define mm_untag_mask mm_untag_mask
+static inline unsigned long mm_untag_mask(struct mm_struct *mm)
+{
+ return mm->context.untag_mask;
+}
+
static inline void mm_reset_untag_mask(struct mm_struct *mm)
{
mm->context.untag_mask = -1UL;
@@ -91,6 +91,7 @@
#include <linux/user_namespace.h>
#include <linux/fs_struct.h>
#include <linux/kthread.h>
+#include <linux/mmu_context.h>
#include <asm/processor.h>
#include "internal.h"
@@ -423,6 +424,11 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
}
+static inline void task_untag_mask(struct seq_file *m, struct mm_struct *mm)
+{
+ seq_printf(m, "untag_mask:\t%#lx\n", mm_untag_mask(mm));
+}
+
int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
@@ -438,6 +444,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
task_mem(m, mm);
task_core_dumping(m, task);
task_thp_status(m, mm);
+ task_untag_mask(m, mm);
mmput(mm);
}
task_sig(m, task);
@@ -28,4 +28,11 @@ static inline void leave_mm(int cpu) { }
# define task_cpu_possible(cpu, p) cpumask_test_cpu((cpu), task_cpu_possible_mask(p))
#endif
+#ifndef mm_untag_mask
+static inline unsigned long mm_untag_mask(struct mm_struct *mm)
+{
+ return -1UL;
+}
+#endif
+
#endif