From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, tglx@linutronix.de, Dave Hansen <dave@sr71.net>,
dave.hansen@linux.intel.com
Subject: [PATCH 10/19] x86, mpx: Trace the attempts to find bounds tables
Date: Mon, 18 May 2015 23:25:32 -0700 [thread overview]
Message-ID: <20150519062532.B3BAC40E@viggo.jf.intel.com> (raw)
In-Reply-To: <20150519062528.E2D5DDFF@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
There are two different events being traced here. They are
doing similar things so share a trace "EVENT_CLASS" and are
presented together.
1. Trace when MPX is zapping pages "mpx_unmap_zap":
When MPX can not free an entire bounds table, it will
instead try to zap unused parts of a bounds table to free
the backing memory. This decreases RSS (resident set
size) without decreasing the virtual space allocated
for bounds tables.
2. Trace attempts to find bounds tables "mpx_unmap_search":
This event traces any time we go looking to unmap a
bounds table for a given virtual address range. This is
useful to ensure that the kernel actually "tried" to free
a bounds table versus times it succeeded in finding one.
It might try and fail if it realized that a table was
shared with an adjacent VMA which is not being unmapped.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---
b/arch/x86/include/asm/trace/mpx.h | 32 ++++++++++++++++++++++++++++++++
b/arch/x86/mm/mpx.c | 2 ++
2 files changed, 34 insertions(+)
diff -puN arch/x86/include/asm/trace/mpx.h~mpx-trace_unmap_zap arch/x86/include/asm/trace/mpx.h
--- a/arch/x86/include/asm/trace/mpx.h~mpx-trace_unmap_zap 2015-05-18 17:49:01.587542414 -0700
+++ b/arch/x86/include/asm/trace/mpx.h 2015-05-18 17:49:01.592542639 -0700
@@ -62,6 +62,38 @@ TRACE_EVENT(bounds_exception_mpx,
__entry->bndstatus)
);
+DECLARE_EVENT_CLASS(mpx_range_trace,
+
+ TP_PROTO(unsigned long start,
+ unsigned long end),
+ TP_ARGS(start, end),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, start)
+ __field(unsigned long, end)
+ ),
+
+ TP_fast_assign(
+ __entry->start = start;
+ __entry->end = end;
+ ),
+
+ TP_printk("[0x%p:0x%p]",
+ (void *)__entry->start,
+ (void *)__entry->end
+ )
+);
+
+DEFINE_EVENT(mpx_range_trace, mpx_unmap_zap,
+ TP_PROTO(unsigned long start, unsigned long end),
+ TP_ARGS(start, end)
+);
+
+DEFINE_EVENT(mpx_range_trace, mpx_unmap_search,
+ TP_PROTO(unsigned long start, unsigned long end),
+ TP_ARGS(start, end)
+);
+
#else
/*
diff -puN arch/x86/mm/mpx.c~mpx-trace_unmap_zap arch/x86/mm/mpx.c
--- a/arch/x86/mm/mpx.c~mpx-trace_unmap_zap 2015-05-18 17:49:01.588542459 -0700
+++ b/arch/x86/mm/mpx.c 2015-05-18 17:49:01.592542639 -0700
@@ -668,6 +668,7 @@ static int zap_bt_entries(struct mm_stru
len = min(vma->vm_end, end) - addr;
zap_page_range(vma, addr, len, NULL);
+ trace_mpx_unmap_zap(addr, addr+len);
vma = vma->vm_next;
addr = vma->vm_start;
@@ -840,6 +841,7 @@ static int mpx_unmap_tables(struct mm_st
long __user *bd_entry, *bde_start, *bde_end;
unsigned long bt_addr;
+ trace_mpx_unmap_search(start, end);
/*
* "Edge" bounds tables are those which are being used by the region
* (start -> end), but that may be shared with adjacent areas. If they
_
next prev parent reply other threads:[~2015-05-19 6:27 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-19 6:25 [PATCH 00/19] x86, mpx updates for 4.2 (take 7) Dave Hansen
2015-05-19 6:25 ` [PATCH 01/19] x86, mpx, xsave: Fix up bad get_xsave_addr() assumptions Dave Hansen
2015-05-19 6:25 ` [PATCH 02/19] x86, fpu: Wrap get_xsave_addr() to make it safer Dave Hansen
2015-05-19 8:15 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 03/19] x86, mpx: Use new get_xsave_field_ptr() Dave Hansen
2015-05-19 8:16 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 04/19] x86, mpx: Cleanup: Do not pass task around when unnecessary Dave Hansen
2015-05-19 8:16 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 05/19] x86, mpx: remove redundant MPX_BNDCFG_ADDR_MASK Dave Hansen
2015-05-19 6:25 ` [PATCH 07/19] x86, mpx: boot-time disable Dave Hansen
2015-05-19 6:25 ` [PATCH 06/19] x86, mpx: Restrict mmap size check to bounds tables Dave Hansen
2015-05-19 6:25 ` [PATCH 08/19] x86, mpx: trace #BR exceptions Dave Hansen
2015-05-19 6:25 ` [PATCH 09/19] x86, mpx: trace entry to bounds exception paths Dave Hansen
2015-05-19 8:17 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 11/19] x86, mpx: trace allocation of new bounds tables Dave Hansen
2015-05-19 6:25 ` Dave Hansen [this message]
2015-05-19 8:17 ` [PATCH 10/19] x86, mpx: Trace the attempts to find " Thomas Gleixner
2015-05-19 6:25 ` [PATCH 13/19] x86, mpx: Add temporary variable to reduce masking Dave Hansen
2015-05-19 6:25 ` [PATCH 12/19] x86: make is_64bit_mm() widely available Dave Hansen
2015-05-19 6:25 ` [PATCH 17/19] x86, mpx: rewrite unmap code Dave Hansen
2015-05-19 6:25 ` [PATCH 15/19] x86, mpx: do 32-bit-only cmpxchg for 32-bit apps Dave Hansen
2015-05-19 8:18 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 14/19] x86, mpx: new directory entry to addr helper Dave Hansen
2015-05-19 6:25 ` [PATCH 16/19] x86, mpx: support 32-bit binaries on 64-bit kernel Dave Hansen
2015-05-19 8:21 ` Thomas Gleixner
2015-05-19 6:25 ` [PATCH 18/19] x86, mpx: do not count MPX VMAs as neighbors when unmapping Dave Hansen
2015-05-19 6:25 ` [PATCH 19/19] x86, mpx: allow mixed binaries again Dave Hansen
2015-05-20 10:05 ` [PATCH 00/19] x86, mpx updates for 4.2 (take 7) Ingo Molnar
2015-05-26 16:49 ` Dave Hansen
2015-05-27 12:18 ` Ingo Molnar
2015-05-27 18:36 [PATCH 00/19] x86, mpx updates for 4.2 (take 8) Dave Hansen
2015-05-27 18:36 ` [PATCH 10/19] x86, mpx: Trace the attempts to find bounds tables Dave Hansen
2015-06-07 18:37 [PATCH 00/19] x86, mpx updates for 4.2 (take 9) Dave Hansen
2015-06-07 18:37 ` [PATCH 10/19] x86, mpx: Trace the attempts to find bounds tables Dave Hansen
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