Subject: [RFC PATCH 0/4] kmemtrace RFC (resend 2)

Hi everyone,

I hopefully fixed all your previous objections. I have also set up a git tree
for anyone who'd like to try kmemtrace (gitweb URL):

http://repo.or.cz/w/linux-2.6/kmemtrace.git

Comment on the patchset and please try running kmemtrace if possible. Check
the docs for information on how to get the userspace tool and set it up.

Important: the kmemtrace-user repo went stable and I'll not alter the revision
history anymore. BTW, don't be scared if you see many errors being reported by
kmemtrace-report, this is a known issue (I could use some advice on this if
you know what's going on).

Changes since last submission:
1. fixed allocator tracing
2. wrote more documentation
3. reworked the ABI and documented it in Documentation/ABI; we don't include
kernel headers in userspace anymore
4. added support for disabling kmemtrace at boot-time
5. added provisions for disabling kmemtrace at runtime
6. changed slab allocators to use __always_inline instead of plain inline,
so that we're sure the return address is valid
7. removed some useless cast, as pointed out by Pekka Enberg

Since the changes were quite extensive, I chose not to preserve any tags such
as "Reviewed-by".

I'm waiting for your input on this.


Thanks,
Eduard

P.S.: Pekka, I followed your advice on adding a field containing the struct
size (managed to make room for it without adding to the current struct size).
This allows us to do crazy stuff in the future, like exporting the whole
stack trace on every allocation. Not sure how useful this is right now, but
let's keep the ABI extensible.


Eduard - Gabriel Munteanu (4):
kmemtrace: Core implementation.
kmemtrace: SLAB hooks.
kmemtrace: SLUB hooks.
kmemtrace: SLOB hooks.

Documentation/ABI/testing/debugfs-kmemtrace | 58 +++++++
Documentation/kernel-parameters.txt | 10 +
Documentation/vm/kmemtrace.txt | 126 ++++++++++++++
MAINTAINERS | 6 +
include/linux/kmemtrace.h | 110 ++++++++++++
include/linux/slab_def.h | 68 +++++++-
include/linux/slob_def.h | 9 +-
include/linux/slub_def.h | 53 ++++++-
init/main.c | 2 +
lib/Kconfig.debug | 28 +++
mm/Makefile | 2 +-
mm/kmemtrace.c | 244 +++++++++++++++++++++++++++
mm/slab.c | 71 +++++++-
mm/slob.c | 37 ++++-
mm/slub.c | 66 +++++++-
15 files changed, 854 insertions(+), 36 deletions(-)
create mode 100644 Documentation/ABI/testing/debugfs-kmemtrace
create mode 100644 Documentation/vm/kmemtrace.txt
create mode 100644 include/linux/kmemtrace.h
create mode 100644 mm/kmemtrace.c


Subject: [RFC PATCH 1/4] kmemtrace: Core implementation.

kmemtrace provides tracing for slab allocator functions, such as kmalloc,
kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected data is then fed
to the userspace application in order to analyse allocation hotspots,
internal fragmentation and so on, making it possible to see how well an
allocator performs, as well as debug and profile kernel code.

Signed-off-by: Eduard - Gabriel Munteanu <[email protected]>
---
Documentation/ABI/testing/debugfs-kmemtrace | 58 +++++++
Documentation/kernel-parameters.txt | 10 +
Documentation/vm/kmemtrace.txt | 126 ++++++++++++++
MAINTAINERS | 6 +
include/linux/kmemtrace.h | 110 ++++++++++++
init/main.c | 2 +
lib/Kconfig.debug | 28 +++
mm/Makefile | 2 +-
mm/kmemtrace.c | 244 +++++++++++++++++++++++++++
9 files changed, 585 insertions(+), 1 deletions(-)
create mode 100644 Documentation/ABI/testing/debugfs-kmemtrace
create mode 100644 Documentation/vm/kmemtrace.txt
create mode 100644 include/linux/kmemtrace.h
create mode 100644 mm/kmemtrace.c

diff --git a/Documentation/ABI/testing/debugfs-kmemtrace b/Documentation/ABI/testing/debugfs-kmemtrace
new file mode 100644
index 0000000..466c2bb
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-kmemtrace
@@ -0,0 +1,58 @@
+What: /sys/kernel/debug/kmemtrace/
+Date: July 2008
+Contact: Eduard - Gabriel Munteanu <[email protected]>
+Description:
+
+In kmemtrace-enabled kernels, the following files are created:
+
+/sys/kernel/debug/kmemtrace/
+ cpu<n> (0400) Per-CPU tracing data, see below. (binary)
+ total_overruns (0400) Total number of bytes which were dropped from
+ cpu<n> files because of full buffer condition,
+ non-binary. (text)
+ abi_version (0400) Kernel's kmemtrace ABI version. (text)
+
+Each per-CPU file should be read according to the relay interface. That is,
+the reader should set affinity to that specific CPU and, as currently done by
+the userspace application (though there are other methods), use poll() with
+an infinite timeout before every read(). Otherwise, erroneous data may be
+read. The binary data has the following _core_ format:
+ Event id (1 byte) Unsigned integer, one of:
+ 0 - erroneous event, this is illegal/invalid data and must
+ not occur (KMEMTRACE_EVENT_NULL)
+ 1 - represents an allocation (KMEMTRACE_EVENT_ALLOC)
+ 2 - represents a freeing of previously allocated memory
+ (KMEMTRACE_EVENT_FREE)
+ Type id (1 byte) Unsigned integer, one of:
+ 0 - this is a kmalloc() / kfree()
+ 1 - this is a kmem_cache_alloc() / kmem_cache_free()
+ 2 - this is a __get_free_pages() et al.
+ Event size (2 bytes) Unsigned integer representing the
+ size of this event. Used to extend
+ kmemtrace. Discard the bytes you
+ don't know about.
+ Target CPU (4 bytes) Signed integer, valid for event id 1.
+ If equal to -1, target CPU is the same
+ as origin CPU, but the reverse might
+ not be true.
+ Caller address (8 bytes) Return address to the caller.
+ Pointer to mem (8 bytes) Pointer to allocated memory, must not
+ be NULL.
+ Requested bytes (8 bytes) Total number of requested bytes,
+ unsigned, must not be zero.
+ Allocated bytes (8 bytes) Total number of actually allocated
+ bytes, unsigned, must not be lower
+ than requested bytes.
+ Requested flags (8 bytes) GFP flags supplied by the caller.
+ Timestamp (8 bytes) Signed integer representing timestamp.
+
+The data is made available in the same endianness the machine has.
+
+Other event ids and type ids may be defined and added. Other fields may be
+added by increasing event size. Every modification to the ABI, including
+new id definitions, are followed by bumping the ABI version by one.
+
+
+Users:
+ kmemtrace-user - git://repo.or.cz/kmemtrace-user.git
+
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b52f47d..446a257 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -49,6 +49,7 @@ parameter is applicable:
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
+ KMEMTRACE kmemtrace is enabled.
LIBATA Libata driver is enabled
LP Printer support is enabled.
LOOP Loopback device support is enabled.
@@ -941,6 +942,15 @@ and is between 256 and 4096 characters. It is defined in the file
use the HighMem zone if it exists, and the Normal
zone if it does not.

+ kmemtrace.enable= [KNL,KMEMTRACE] Format: { yes | no }
+ Controls whether kmemtrace is enabled
+ at boot-time.
+
+ kmemtrace.subbufs=n [KNL,KMEMTRACE] Overrides the number of
+ subbufs kmemtrace's relay channel has. Set this
+ higher than default (KMEMTRACE_N_SUBBUFS in code) if
+ you experience buffer overruns.
+
movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
is similar to kernelcore except it specifies the
amount of memory used for migratable allocations.
diff --git a/Documentation/vm/kmemtrace.txt b/Documentation/vm/kmemtrace.txt
new file mode 100644
index 0000000..75360b1
--- /dev/null
+++ b/Documentation/vm/kmemtrace.txt
@@ -0,0 +1,126 @@
+ kmemtrace - Kernel Memory Tracer
+
+ by Eduard - Gabriel Munteanu
+ <[email protected]>
+
+I. Introduction
+===============
+
+kmemtrace helps kernel developers figure out two things:
+1) how different allocators (SLAB, SLUB etc.) perform
+2) how kernel code allocates memory and how much
+
+To do this, we trace every allocation and export information to the userspace
+through the relay interface. We export things such as the number of requested
+bytes, the number of bytes actually allocated (i.e. including internal
+fragmentation), whether this is a slab allocation or a plain kmalloc() and so
+on.
+
+The actual analysis is performed by a userspace tool (see section III for
+details on where to get it from). It logs the data exported by the kernel,
+processes it and (as of writing this) can provide the following information:
+- the total amount of memory allocated and fragmentation per call-site
+- the amount of memory allocated and fragmentation per allocation
+- total memory allocated and fragmentation in the collected dataset
+- number of cross-CPU allocation and frees (makes sense in NUMA environments)
+
+Moreover, it can potentially find inconsistent and erroneous behavior in
+kernel code, such as using slab free functions on kmalloc'ed memory or
+allocating less memory than requested (but not truly failed allocations).
+
+kmemtrace also makes provisions for tracing on some arch and analysing the
+data on another.
+
+II. Design and goals
+====================
+
+kmemtrace was designed to handle rather large amounts of data. Thus, it uses
+the relay interface to export whatever is logged to userspace, which then
+stores it. Analysis and reporting is done asynchronously, that is, after the
+data is collected and stored. By design, it allows one to log and analyse
+on different machines and different arches.
+
+As of writing this, the ABI is not considered stable, though it might not
+change much. However, no guarantees are made about compatibility yet. When
+deemed stable, the ABI should still allow easy extension while maintaining
+backward compatibility. This is described further in Documentation/ABI.
+
+Summary of design goals:
+ - allow logging and analysis to be done across different machines
+ - be fast and anticipate usage in high-load environments (*)
+ - be reasonably extensible
+ - make it possible for GNU/Linux distributions to have kmemtrace
+ included in their repositories
+
+(*) - one of the reasons Pekka Enberg's original userspace data analysis
+ tool's code was rewritten from Perl to C (although this is more than a
+ simple conversion)
+
+
+III. Quick usage guide
+======================
+
+1) Get a kernel that supports kmemtrace and build it accordingly (i.e. enable
+CONFIG_KMEMTRACE and CONFIG_DEFAULT_ENABLED).
+
+2) Get the userspace tool and build it:
+$ git-clone git://repo.or.cz/kmemtrace-user.git # current repository
+$ cd kmemtrace-user/
+$ ./autogen.sh
+$ ./configure
+$ make
+
+3) Boot the kmemtrace-enabled kernel if you haven't, preferably in the
+'single' runlevel (so that relay buffers don't fill up easily), and run
+kmemtrace:
+# '$' does not mean user, but root here.
+$ mount -t debugfs none /sys/kernel/debug
+$ mount -t proc none /proc
+$ cd path/to/kmemtrace-user/
+$ ./kmemtraced
+Wait a bit, then stop it with CTRL+C.
+$ cat /sys/kernel/debug/kmemtrace/total_overruns # Check if we didn't
+ # overrun, should
+ # be zero.
+$ (Optionally) [Run kmemtrace_check separately on each cpu[0-9]*.out file to
+ check its correctness]
+$ ./kmemtrace-report
+
+Now you should have a nice and short summary of how the allocator performs.
+
+IV. FAQ and known issues
+========================
+
+Q: 'cat /sys/kernel/debug/kmemtrace/total_overruns' is non-zero, how do I fix
+this? Should I worry?
+A: If it's non-zero, this affects kmemtrace's accuracy, depending on how
+large the number is. You can fix it by supplying a higher
+'kmemtrace.subbufs=N' kernel parameter.
+---
+
+Q: kmemtrace_check reports errors, how do I fix this? Should I worry?
+A: This is a bug and should be reported. It can occur for a variety of
+reasons:
+ - possible bugs in relay code
+ - possible misuse of relay by kmemtrace
+ - timestamps being collected unorderly
+Or you may fix it yourself and send us a patch.
+---
+
+Q: kmemtrace_report shows many errors, how do I fix this? Should I worry?
+A: This is a known issue and I'm working on it. These might be true errors
+in kernel code, which may have inconsistent behavior (e.g. allocating memory
+with kmem_cache_alloc() and freeing it with kfree()). Pekka Enberg pointed
+out this behavior may work with SLAB, but may fail with other allocators.
+
+It may also be due to lack of tracing in some unusual allocator functions.
+
+We don't want bug reports regarding this issue yet.
+---
+
+V. See also
+===========
+
+Documentation/kernel-parameters.txt
+Documentation/ABI/testing/debugfs-kmemtrace
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 56a2f67..e967bc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2425,6 +2425,12 @@ M: [email protected]
L: [email protected]
S: Maintained

+KMEMTRACE
+P: Eduard - Gabriel Munteanu
+M: [email protected]
+L: [email protected]
+S: Maintained
+
KPROBES
P: Ananth N Mavinakayanahalli
M: [email protected]
diff --git a/include/linux/kmemtrace.h b/include/linux/kmemtrace.h
new file mode 100644
index 0000000..48746ee
--- /dev/null
+++ b/include/linux/kmemtrace.h
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2008 Eduard - Gabriel Munteanu
+ *
+ * This file is released under GPL version 2.
+ */
+
+#ifndef _LINUX_KMEMTRACE_H
+#define _LINUX_KMEMTRACE_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/marker.h>
+
+/* ABI definition starts here. */
+
+#define KMEMTRACE_ABI_VERSION 1
+
+enum kmemtrace_event_id {
+ KMEMTRACE_EVENT_NULL = 0, /* Erroneous event. */
+ KMEMTRACE_EVENT_ALLOC,
+ KMEMTRACE_EVENT_FREE,
+};
+
+enum kmemtrace_type_id {
+ KMEMTRACE_TYPE_KMALLOC = 0, /* kmalloc() / kfree(). */
+ KMEMTRACE_TYPE_CACHE, /* kmem_cache_*(). */
+ KMEMTRACE_TYPE_PAGES, /* __get_free_pages() and friends. */
+};
+
+struct kmemtrace_event {
+ u8 event_id; /* Allocate or free? */
+ u8 type_id; /* Kind of allocation/free. */
+ u16 event_size; /* Size of event */
+ s32 node; /* Target CPU. */
+ u64 call_site; /* Caller address. */
+ u64 ptr; /* Pointer to allocation. */
+ u64 bytes_req; /* Number of bytes requested. */
+ u64 bytes_alloc; /* Number of bytes allocated. */
+ u64 gfp_flags; /* Requested flags. */
+ s64 timestamp; /* When the operation occured in ns. */
+} __attribute__ ((__packed__));
+
+/* End of ABI definition. */
+
+#ifdef CONFIG_KMEMTRACE
+
+extern void kmemtrace_init(void);
+
+static inline void kmemtrace_mark_alloc_node(enum kmemtrace_type_id type_id,
+ unsigned long call_site,
+ const void *ptr,
+ size_t bytes_req,
+ size_t bytes_alloc,
+ gfp_t gfp_flags,
+ int node)
+{
+ trace_mark(kmemtrace_alloc, "type_id %d call_site %lu ptr %lu "
+ "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d",
+ type_id, call_site, (unsigned long) ptr,
+ bytes_req, bytes_alloc, (unsigned long) gfp_flags, node);
+}
+
+static inline void kmemtrace_mark_free(enum kmemtrace_type_id type_id,
+ unsigned long call_site,
+ const void *ptr)
+{
+ trace_mark(kmemtrace_free, "type_id %d call_site %lu ptr %lu",
+ type_id, call_site, (unsigned long) ptr);
+}
+
+#else /* CONFIG_KMEMTRACE */
+
+static inline void kmemtrace_init(void)
+{
+}
+
+static inline void kmemtrace_mark_alloc_node(enum kmemtrace_type_id type_id,
+ unsigned long call_site,
+ const void *ptr,
+ size_t bytes_req,
+ size_t bytes_alloc,
+ gfp_t gfp_flags,
+ int node)
+{
+}
+
+static inline void kmemtrace_mark_free(enum kmemtrace_type_id type_id,
+ unsigned long call_site,
+ const void *ptr)
+{
+}
+
+#endif /* CONFIG_KMEMTRACE */
+
+static inline void kmemtrace_mark_alloc(enum kmemtrace_type_id type_id,
+ unsigned long call_site,
+ const void *ptr,
+ size_t bytes_req,
+ size_t bytes_alloc,
+ gfp_t gfp_flags)
+{
+ kmemtrace_mark_alloc_node(type_id, call_site, ptr,
+ bytes_req, bytes_alloc, gfp_flags, -1);
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_KMEMTRACE_H */
+
diff --git a/init/main.c b/init/main.c
index 057f364..c00659c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -66,6 +66,7 @@
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
+#include <linux/kmemtrace.h>

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/smp.h>
@@ -641,6 +642,7 @@ asmlinkage void __init start_kernel(void)
enable_debug_pagealloc();
cpu_hotplug_init();
kmem_cache_init();
+ kmemtrace_init();
debug_objects_mem_init();
idr_init_cache();
setup_per_cpu_pageset();
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d2099f4..0ade2ae 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -674,6 +674,34 @@ config FIREWIRE_OHCI_REMOTE_DMA

If unsure, say N.

+config KMEMTRACE
+ bool "Kernel memory tracer (kmemtrace)"
+ depends on RELAY && DEBUG_FS && MARKERS
+ help
+ kmemtrace provides tracing for slab allocator functions, such as
+ kmalloc, kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected
+ data is then fed to the userspace application in order to analyse
+ allocation hotspots, internal fragmentation and so on, making it
+ possible to see how well an allocator performs, as well as debug
+ and profile kernel code.
+
+ This requires an userspace application to use. See
+ Documentation/vm/kmemtrace.txt for more information.
+
+ Saying Y will make the kernel somewhat larger and slower. However,
+ if you disable kmemtrace at run-time or boot-time, the performance
+ impact is minimal (depending on the arch the kernel is built for).
+
+ If unsure, say N.
+
+config KMEMTRACE_DEFAULT_ENABLED
+ bool "Enabled by default at boot"
+ depends on KMEMTRACE
+ help
+ Say Y here to enable kmemtrace at boot-time by default. Whatever
+ the choice, the behavior can be overridden by a kernel parameter,
+ as described in documentation.
+
source "samples/Kconfig"

source "lib/Kconfig.kgdb"
diff --git a/mm/Makefile b/mm/Makefile
index 18c143b..d88a3bc 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -33,4 +33,4 @@ obj-$(CONFIG_MIGRATION) += migrate.o
obj-$(CONFIG_SMP) += allocpercpu.o
obj-$(CONFIG_QUICKLIST) += quicklist.o
obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o
-
+obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
diff --git a/mm/kmemtrace.c b/mm/kmemtrace.c
new file mode 100644
index 0000000..4b33ace
--- /dev/null
+++ b/mm/kmemtrace.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2008 Pekka Enberg, Eduard - Gabriel Munteanu
+ *
+ * This file is released under GPL version 2.
+ */
+
+#include <linux/string.h>
+#include <linux/debugfs.h>
+#include <linux/relay.h>
+#include <linux/module.h>
+#include <linux/marker.h>
+#include <linux/gfp.h>
+#include <linux/kmemtrace.h>
+
+#define KMEMTRACE_SUBBUF_SIZE (8192 * sizeof(struct kmemtrace_event))
+#define KMEMTRACE_N_SUBBUFS 20
+
+static struct rchan *kmemtrace_chan;
+static u32 kmemtrace_buf_overruns;
+
+static unsigned int kmemtrace_n_subbufs;
+#ifdef CONFIG_KMEMTRACE_DEFAULT_ENABLED
+static unsigned int kmemtrace_enabled = 1;
+#else
+static unsigned int kmemtrace_enabled = 0;
+#endif
+
+static u32 kmemtrace_abi_version __read_mostly = KMEMTRACE_ABI_VERSION;
+
+static inline void kmemtrace_log_event(struct kmemtrace_event *event)
+{
+ relay_write(kmemtrace_chan, event, sizeof(struct kmemtrace_event));
+}
+
+static void kmemtrace_probe_alloc(void *probe_data, void *call_data,
+ const char *format, va_list *args)
+{
+ unsigned long flags;
+ struct kmemtrace_event ev;
+
+ /*
+ * Don't convert this to use structure initializers,
+ * C99 does not guarantee the rvalues evaluation order.
+ */
+ ev.event_id = KMEMTRACE_EVENT_ALLOC;
+ ev.type_id = va_arg(*args, int);
+ ev.event_size = sizeof(struct kmemtrace_event);
+ ev.call_site = va_arg(*args, unsigned long);
+ ev.ptr = va_arg(*args, unsigned long);
+ /* Don't trace ignored allocations. */
+ if (!ev.ptr)
+ return;
+ ev.bytes_req = va_arg(*args, unsigned long);
+ ev.bytes_alloc = va_arg(*args, unsigned long);
+ /* ev.timestamp set below, to preserve event ordering. */
+ ev.gfp_flags = va_arg(*args, unsigned long);
+ ev.node = va_arg(*args, int);
+
+ /* We disable IRQs for timestamps to match event ordering. */
+ local_irq_save(flags);
+ ev.timestamp = ktime_to_ns(ktime_get());
+ kmemtrace_log_event(&ev);
+ local_irq_restore(flags);
+}
+
+static void kmemtrace_probe_free(void *probe_data, void *call_data,
+ const char *format, va_list *args)
+{
+ unsigned long flags;
+ struct kmemtrace_event ev;
+
+ /*
+ * Don't convert this to use structure initializers,
+ * C99 does not guarantee the rvalues evaluation order.
+ */
+ ev.event_id = KMEMTRACE_EVENT_FREE;
+ ev.type_id = va_arg(*args, int);
+ ev.event_size = sizeof(struct kmemtrace_event);
+ ev.call_site = va_arg(*args, unsigned long);
+ ev.ptr = va_arg(*args, unsigned long);
+ /* Don't trace ignored allocations. */
+ if (!ev.ptr)
+ return;
+ /* ev.timestamp set below, to preserve event ordering. */
+
+ /* We disable IRQs for timestamps to match event ordering. */
+ local_irq_save(flags);
+ ev.timestamp = ktime_to_ns(ktime_get());
+ kmemtrace_log_event(&ev);
+ local_irq_restore(flags);
+}
+
+static struct dentry *
+kmemtrace_create_buf_file(const char *filename, struct dentry *parent,
+ int mode, struct rchan_buf *buf, int *is_global)
+{
+ return debugfs_create_file(filename, mode, parent, buf,
+ &relay_file_operations);
+}
+
+static int kmemtrace_remove_buf_file(struct dentry *dentry)
+{
+ debugfs_remove(dentry);
+
+ return 0;
+}
+
+static int kmemtrace_count_overruns(struct rchan_buf *buf,
+ void *subbuf, void *prev_subbuf,
+ size_t prev_padding)
+{
+ if (relay_buf_full(buf)) {
+ /*
+ * We know it's not SMP-safe, but neither
+ * debugfs_create_u32() is.
+ */
+ kmemtrace_buf_overruns++;
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct rchan_callbacks relay_callbacks = {
+ .create_buf_file = kmemtrace_create_buf_file,
+ .remove_buf_file = kmemtrace_remove_buf_file,
+ .subbuf_start = kmemtrace_count_overruns,
+};
+
+static struct dentry *kmemtrace_dir;
+static struct dentry *kmemtrace_overruns_dentry;
+static struct dentry *kmemtrace_abi_version_dentry;
+
+static void kmemtrace_cleanup(void)
+{
+ marker_probe_unregister("kmemtrace_alloc", kmemtrace_probe_alloc, NULL);
+ marker_probe_unregister("kmemtrace_free", kmemtrace_probe_free, NULL);
+
+ if (kmemtrace_abi_version_dentry)
+ debugfs_remove(kmemtrace_abi_version_dentry);
+ if (kmemtrace_overruns_dentry)
+ debugfs_remove(kmemtrace_overruns_dentry);
+
+ relay_close(kmemtrace_chan);
+ kmemtrace_chan = NULL;
+
+ if (kmemtrace_dir)
+ debugfs_remove(kmemtrace_dir);
+}
+
+static int __init kmemtrace_setup_late(void)
+{
+ if (!kmemtrace_chan)
+ goto failed;
+
+ kmemtrace_dir = debugfs_create_dir("kmemtrace", NULL);
+ if (!kmemtrace_dir)
+ goto cleanup;
+
+ kmemtrace_abi_version_dentry =
+ debugfs_create_u32("abi_version", S_IRUSR,
+ kmemtrace_dir, &kmemtrace_abi_version);
+ kmemtrace_overruns_dentry =
+ debugfs_create_u32("total_overruns", S_IRUSR,
+ kmemtrace_dir, &kmemtrace_buf_overruns);
+ if (!kmemtrace_overruns_dentry || !kmemtrace_abi_version_dentry)
+ goto cleanup;
+
+ if (relay_late_setup_files(kmemtrace_chan, "cpu", kmemtrace_dir))
+ goto cleanup;
+
+ printk(KERN_INFO "kmemtrace: fully up.\n");
+
+ return 0;
+
+cleanup:
+ kmemtrace_cleanup();
+failed:
+ return 1;
+}
+late_initcall(kmemtrace_setup_late);
+
+static int __init kmemtrace_set_boot_enabled(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "yes"))
+ kmemtrace_enabled = 1;
+ else if (!strcmp(str, "no"))
+ kmemtrace_enabled = 0;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+early_param("kmemtrace.enable", kmemtrace_set_boot_enabled);
+
+static int __init kmemtrace_set_subbufs(char *str)
+{
+ get_option(&str, &kmemtrace_n_subbufs);
+ return 0;
+}
+early_param("kmemtrace.subbufs", kmemtrace_set_subbufs);
+
+void kmemtrace_init(void)
+{
+ int err;
+
+ if (!kmemtrace_enabled)
+ return;
+
+ if (!kmemtrace_n_subbufs)
+ kmemtrace_n_subbufs = KMEMTRACE_N_SUBBUFS;
+
+ kmemtrace_chan = relay_open(NULL, NULL, KMEMTRACE_SUBBUF_SIZE,
+ kmemtrace_n_subbufs, &relay_callbacks,
+ NULL);
+ if (!kmemtrace_chan) {
+ printk(KERN_INFO "kmemtrace: could not open relay channel\n");
+ return;
+ }
+
+ err = marker_probe_register("kmemtrace_alloc", "type_id %d "
+ "call_site %lu ptr %lu "
+ "bytes_req %lu bytes_alloc %lu "
+ "gfp_flags %lu node %d",
+ kmemtrace_probe_alloc, NULL);
+ if (err)
+ goto probe_fail;
+ err = marker_probe_register("kmemtrace_free", "type_id %d "
+ "call_site %lu ptr %lu",
+ kmemtrace_probe_free, NULL);
+ if (err)
+ goto probe_fail;
+
+ printk(KERN_INFO "kmemtrace: early init successful.\n");
+ return;
+
+probe_fail:
+ printk(KERN_INFO "kmemtrace: could not register marker probes!\n");
+ kmemtrace_cleanup();
+}
+
--
1.5.6.1

Subject: [RFC PATCH 2/4] kmemtrace: SLAB hooks.

This adds hooks for the SLAB allocator, to allow tracing with kmemtrace.

Signed-off-by: Eduard - Gabriel Munteanu <[email protected]>
---
include/linux/slab_def.h | 68 ++++++++++++++++++++++++++++++++++++++------
mm/slab.c | 71 +++++++++++++++++++++++++++++++++++++++++----
2 files changed, 123 insertions(+), 16 deletions(-)

diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 39c3a5e..7555ce9 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -14,6 +14,7 @@
#include <asm/page.h> /* kmalloc_sizes.h needs PAGE_SIZE */
#include <asm/cache.h> /* kmalloc_sizes.h needs L1_CACHE_BYTES */
#include <linux/compiler.h>
+#include <linux/kmemtrace.h>

/* Size description struct for general caches. */
struct cache_sizes {
@@ -28,8 +29,26 @@ extern struct cache_sizes malloc_sizes[];
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);

-static inline void *kmalloc(size_t size, gfp_t flags)
+#ifdef CONFIG_KMEMTRACE
+extern void *kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags);
+extern size_t slab_buffer_size(struct kmem_cache *cachep);
+#else
+static __always_inline void *
+kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags)
{
+ return kmem_cache_alloc(cachep, flags);
+}
+static inline size_t slab_buffer_size(struct kmem_cache *cachep)
+{
+ return 0;
+}
+#endif
+
+static __always_inline void *kmalloc(size_t size, gfp_t flags)
+{
+ struct kmem_cache *cachep;
+ void *ret;
+
if (__builtin_constant_p(size)) {
int i = 0;

@@ -50,10 +69,17 @@ static inline void *kmalloc(size_t size, gfp_t flags)
found:
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
- return kmem_cache_alloc(malloc_sizes[i].cs_dmacachep,
- flags);
+ cachep = malloc_sizes[i].cs_dmacachep;
+ else
#endif
- return kmem_cache_alloc(malloc_sizes[i].cs_cachep, flags);
+ cachep = malloc_sizes[i].cs_cachep;
+
+ ret = kmem_cache_alloc_notrace(cachep, flags);
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC, _THIS_IP_, ret,
+ size, slab_buffer_size(cachep), flags);
+
+ return ret;
}
return __kmalloc(size, flags);
}
@@ -62,8 +88,25 @@ found:
extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);

-static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
+#ifdef CONFIG_KMEMTRACE
+extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
+ gfp_t flags,
+ int nodeid);
+#else
+static __always_inline void *
+kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
+ gfp_t flags,
+ int nodeid)
+{
+ return kmem_cache_alloc_node(cachep, flags, nodeid);
+}
+#endif
+
+static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
+ struct kmem_cache *cachep;
+ void *ret;
+
if (__builtin_constant_p(size)) {
int i = 0;

@@ -84,11 +127,18 @@ static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
found:
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
- return kmem_cache_alloc_node(malloc_sizes[i].cs_dmacachep,
- flags, node);
+ cachep = malloc_sizes[i].cs_dmacachep;
+ else
#endif
- return kmem_cache_alloc_node(malloc_sizes[i].cs_cachep,
- flags, node);
+ cachep = malloc_sizes[i].cs_cachep;
+
+ ret = kmem_cache_alloc_node_notrace(cachep, flags, node);
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC, _THIS_IP_,
+ ret, size, slab_buffer_size(cachep),
+ flags, node);
+
+ return ret;
}
return __kmalloc_node(size, flags, node);
}
diff --git a/mm/slab.c b/mm/slab.c
index 046607f..1496962 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -111,6 +111,7 @@
#include <linux/rtmutex.h>
#include <linux/reciprocal_div.h>
#include <linux/debugobjects.h>
+#include <linux/kmemtrace.h>

#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -567,6 +568,14 @@ static void **dbg_userword(struct kmem_cache *cachep, void *objp)

#endif

+#ifdef CONFIG_KMEMTRACE
+size_t slab_buffer_size(struct kmem_cache *cachep)
+{
+ return cachep->buffer_size;
+}
+EXPORT_SYMBOL(slab_buffer_size);
+#endif
+
/*
* Do not go above this order unless 0 objects fit into the slab.
*/
@@ -3621,10 +3630,23 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp)
*/
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
{
- return __cache_alloc(cachep, flags, __builtin_return_address(0));
+ void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_CACHE, _RET_IP_, ret,
+ obj_size(cachep), cachep->buffer_size, flags);
+
+ return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc);

+#ifdef CONFIG_KMEMTRACE
+void *kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags)
+{
+ return __cache_alloc(cachep, flags, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(kmem_cache_alloc_notrace);
+#endif
+
/**
* kmem_ptr_validate - check if an untrusted pointer might be a slab entry.
* @cachep: the cache we're checking against
@@ -3669,23 +3691,47 @@ out:
#ifdef CONFIG_NUMA
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
- return __cache_alloc_node(cachep, flags, nodeid,
- __builtin_return_address(0));
+ void *ret = __cache_alloc_node(cachep, flags, nodeid,
+ __builtin_return_address(0));
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_CACHE, _RET_IP_, ret,
+ obj_size(cachep), cachep->buffer_size,
+ flags, nodeid);
+
+ return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc_node);

+#ifdef CONFIG_KMEMTRACE
+void *kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
+ gfp_t flags,
+ int nodeid)
+{
+ return __cache_alloc_node(cachep, flags, nodeid,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node_notrace);
+#endif
+
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
{
struct kmem_cache *cachep;
+ void *ret;

cachep = kmem_find_general_cachep(size, flags);
if (unlikely(ZERO_OR_NULL_PTR(cachep)))
return cachep;
- return kmem_cache_alloc_node(cachep, flags, node);
+ ret = kmem_cache_alloc_node_notrace(cachep, flags, node);
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+ (unsigned long) caller, ret,
+ size, cachep->buffer_size, flags, node);
+
+ return ret;
}

-#ifdef CONFIG_DEBUG_SLAB
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_KMEMTRACE)
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
return __do_kmalloc_node(size, flags, node,
@@ -3718,6 +3764,7 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
void *caller)
{
struct kmem_cache *cachep;
+ void *ret;

/* If you want to save a few bytes .text space: replace
* __ with kmem_.
@@ -3727,11 +3774,17 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
cachep = __find_general_cachep(size, flags);
if (unlikely(ZERO_OR_NULL_PTR(cachep)))
return cachep;
- return __cache_alloc(cachep, flags, caller);
+ ret = __cache_alloc(cachep, flags, caller);
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC,
+ (unsigned long) caller, ret,
+ size, cachep->buffer_size, flags);
+
+ return ret;
}


-#ifdef CONFIG_DEBUG_SLAB
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_KMEMTRACE)
void *__kmalloc(size_t size, gfp_t flags)
{
return __do_kmalloc(size, flags, __builtin_return_address(0));
@@ -3770,6 +3823,8 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
debug_check_no_obj_freed(objp, obj_size(cachep));
__cache_free(cachep, objp);
local_irq_restore(flags);
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_CACHE, _RET_IP_, objp);
}
EXPORT_SYMBOL(kmem_cache_free);

@@ -3796,6 +3851,8 @@ void kfree(const void *objp)
debug_check_no_obj_freed(objp, obj_size(c));
__cache_free(c, (void *)objp);
local_irq_restore(flags);
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_KMALLOC, _RET_IP_, objp);
}
EXPORT_SYMBOL(kfree);

--
1.5.6.1

Subject: [RFC PATCH 4/4] kmemtrace: SLOB hooks.

This adds hooks for the SLOB allocator, to allow tracing with kmemtrace.

Signed-off-by: Eduard - Gabriel Munteanu <[email protected]>
---
include/linux/slob_def.h | 9 +++++----
mm/slob.c | 37 +++++++++++++++++++++++++++++++------
2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/include/linux/slob_def.h b/include/linux/slob_def.h
index 59a3fa4..0ec00b3 100644
--- a/include/linux/slob_def.h
+++ b/include/linux/slob_def.h
@@ -3,14 +3,15 @@

void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);

-static inline void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+static __always_inline void *kmem_cache_alloc(struct kmem_cache *cachep,
+ gfp_t flags)
{
return kmem_cache_alloc_node(cachep, flags, -1);
}

void *__kmalloc_node(size_t size, gfp_t flags, int node);

-static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
+static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
return __kmalloc_node(size, flags, node);
}
@@ -23,12 +24,12 @@ static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
* kmalloc is the normal method of allocating memory
* in the kernel.
*/
-static inline void *kmalloc(size_t size, gfp_t flags)
+static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
return __kmalloc_node(size, flags, -1);
}

-static inline void *__kmalloc(size_t size, gfp_t flags)
+static __always_inline void *__kmalloc(size_t size, gfp_t flags)
{
return kmalloc(size, flags);
}
diff --git a/mm/slob.c b/mm/slob.c
index a3ad667..23375ed 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -65,6 +65,7 @@
#include <linux/module.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
+#include <linux/kmemtrace.h>
#include <asm/atomic.h>

/*
@@ -463,27 +464,38 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node)
{
unsigned int *m;
int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
+ void *ret;

if (size < PAGE_SIZE - align) {
if (!size)
return ZERO_SIZE_PTR;

m = slob_alloc(size + align, gfp, align, node);
+
if (!m)
return NULL;
*m = size;
- return (void *)m + align;
+ ret = (void *)m + align;
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+ _RET_IP_, ret,
+ size, size + align, gfp, node);
} else {
- void *ret;
+ unsigned int order = get_order(size);

- ret = slob_new_page(gfp | __GFP_COMP, get_order(size), node);
+ ret = slob_new_page(gfp | __GFP_COMP, order, node);
if (ret) {
struct page *page;
page = virt_to_page(ret);
page->private = size;
}
- return ret;
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+ _RET_IP_, ret,
+ size, PAGE_SIZE << order, gfp, node);
}
+
+ return ret;
}
EXPORT_SYMBOL(__kmalloc_node);

@@ -501,6 +513,8 @@ void kfree(const void *block)
slob_free(m, *m + align);
} else
put_page(&sp->page);
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_KMALLOC, _RET_IP_, block);
}
EXPORT_SYMBOL(kfree);

@@ -569,10 +583,19 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
{
void *b;

- if (c->size < PAGE_SIZE)
+ if (c->size < PAGE_SIZE) {
b = slob_alloc(c->size, flags, c->align, node);
- else
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_CACHE,
+ _RET_IP_, b, c->size,
+ SLOB_UNITS(c->size) * SLOB_UNIT,
+ flags, node);
+ } else {
b = slob_new_page(flags, get_order(c->size), node);
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_CACHE,
+ _RET_IP_, b, c->size,
+ PAGE_SIZE << get_order(c->size),
+ flags, node);
+ }

if (c->ctor)
c->ctor(c, b);
@@ -608,6 +631,8 @@ void kmem_cache_free(struct kmem_cache *c, void *b)
} else {
__kmem_cache_free(b, c->size);
}
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_CACHE, _RET_IP_, b);
}
EXPORT_SYMBOL(kmem_cache_free);

--
1.5.6.1

Subject: [RFC PATCH 3/4] kmemtrace: SLUB hooks.

This adds hooks for the SLUB allocator, to allow tracing with kmemtrace.

Signed-off-by: Eduard - Gabriel Munteanu <[email protected]>
---
include/linux/slub_def.h | 53 ++++++++++++++++++++++++++++++++++--
mm/slub.c | 66 +++++++++++++++++++++++++++++++++++++++++----
2 files changed, 110 insertions(+), 9 deletions(-)

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index d117ea2..d77012a 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -10,6 +10,7 @@
#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/kobject.h>
+#include <linux/kmemtrace.h>

enum stat_item {
ALLOC_FASTPATH, /* Allocation from cpu slab */
@@ -203,13 +204,31 @@ static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);

+#ifdef CONFIG_KMEMTRACE
+extern void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags);
+#else
+static __always_inline void *
+kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
+{
+ return kmem_cache_alloc(s, gfpflags);
+}
+#endif
+
static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
{
- return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
+ unsigned int order = get_order(size);
+ void *ret = (void *) __get_free_pages(flags, order);
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC, _THIS_IP_, ret,
+ size, PAGE_SIZE << order, flags);
+
+ return ret;
}

static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
+ void *ret;
+
if (__builtin_constant_p(size)) {
if (size > PAGE_SIZE)
return kmalloc_large(size, flags);
@@ -220,7 +239,13 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
if (!s)
return ZERO_SIZE_PTR;

- return kmem_cache_alloc(s, flags);
+ ret = kmem_cache_alloc_notrace(s, flags);
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC,
+ _THIS_IP_, ret,
+ size, s->size, flags);
+
+ return ret;
}
}
return __kmalloc(size, flags);
@@ -230,8 +255,24 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
void *__kmalloc_node(size_t size, gfp_t flags, int node);
void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);

+#ifdef CONFIG_KMEMTRACE
+extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node);
+#else
+static __always_inline void *
+kmem_cache_alloc_node_notrace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node)
+{
+ return kmem_cache_alloc_node(s, gfpflags, node);
+}
+#endif
+
static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
+ void *ret;
+
if (__builtin_constant_p(size) &&
size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
@@ -239,7 +280,13 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
if (!s)
return ZERO_SIZE_PTR;

- return kmem_cache_alloc_node(s, flags, node);
+ ret = kmem_cache_alloc_node_notrace(s, flags, node);
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+ _THIS_IP_, ret,
+ size, s->size, flags, node);
+
+ return ret;
}
return __kmalloc_node(size, flags, node);
}
diff --git a/mm/slub.c b/mm/slub.c
index 315c392..940145f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -23,6 +23,7 @@
#include <linux/kallsyms.h>
#include <linux/memory.h>
#include <linux/math64.h>
+#include <linux/kmemtrace.h>

/*
* Lock order:
@@ -1652,18 +1653,47 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,

void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
{
- return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
+ void *ret = slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_CACHE, _RET_IP_, ret,
+ s->objsize, s->size, gfpflags);
+
+ return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc);

+#ifdef CONFIG_KMEMTRACE
+void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
+{
+ return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(kmem_cache_alloc_notrace);
+#endif
+
#ifdef CONFIG_NUMA
void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
{
- return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
+ void *ret = slab_alloc(s, gfpflags, node,
+ __builtin_return_address(0));
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_CACHE, _RET_IP_, ret,
+ s->objsize, s->size, gfpflags, node);
+
+ return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc_node);
#endif

+#ifdef CONFIG_KMEMTRACE
+void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node)
+{
+ return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node_notrace);
+#endif
+
/*
* Slow patch handling. This may still be called frequently since objects
* have a longer lifetime than the cpu slabs in most processing loads.
@@ -1771,6 +1801,8 @@ void kmem_cache_free(struct kmem_cache *s, void *x)
page = virt_to_head_page(x);

slab_free(s, page, x, __builtin_return_address(0));
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_CACHE, _RET_IP_, x);
}
EXPORT_SYMBOL(kmem_cache_free);

@@ -2676,6 +2708,7 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
void *__kmalloc(size_t size, gfp_t flags)
{
struct kmem_cache *s;
+ void *ret;

if (unlikely(size > PAGE_SIZE))
return kmalloc_large(size, flags);
@@ -2685,7 +2718,12 @@ void *__kmalloc(size_t size, gfp_t flags)
if (unlikely(ZERO_OR_NULL_PTR(s)))
return s;

- return slab_alloc(s, flags, -1, __builtin_return_address(0));
+ ret = slab_alloc(s, flags, -1, __builtin_return_address(0));
+
+ kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC, _RET_IP_, ret,
+ size, s->size, flags);
+
+ return ret;
}
EXPORT_SYMBOL(__kmalloc);

@@ -2704,16 +2742,30 @@ static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
struct kmem_cache *s;
+ void *ret;

- if (unlikely(size > PAGE_SIZE))
- return kmalloc_large_node(size, flags, node);
+ if (unlikely(size > PAGE_SIZE)) {
+ ret = kmalloc_large_node(size, flags, node);
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+ _RET_IP_, ret,
+ size, PAGE_SIZE << get_order(size),
+ flags, node);
+
+ return ret;
+ }

s = get_slab(size, flags);

if (unlikely(ZERO_OR_NULL_PTR(s)))
return s;

- return slab_alloc(s, flags, node, __builtin_return_address(0));
+ ret = slab_alloc(s, flags, node, __builtin_return_address(0));
+
+ kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC, _RET_IP_, ret,
+ size, s->size, flags, node);
+
+ return ret;
}
EXPORT_SYMBOL(__kmalloc_node);
#endif
@@ -2771,6 +2823,8 @@ void kfree(const void *x)
return;
}
slab_free(page->slab, page, object, __builtin_return_address(0));
+
+ kmemtrace_mark_free(KMEMTRACE_TYPE_KMALLOC, _RET_IP_, x);
}
EXPORT_SYMBOL(kfree);

--
1.5.6.1

2008-07-22 21:30:59

by Frank Ch. Eigler

[permalink] [raw]
Subject: Re: [RFC PATCH 1/4] kmemtrace: Core implementation.


Eduard - Gabriel Munteanu <[email protected]> writes:

> kmemtrace provides tracing for slab allocator functions, such as kmalloc,
> kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected data is then fed
> to the userspace application in order to analyse allocation hotspots,
> internal fragmentation and so on, making it possible to see how well an
> allocator performs, as well as debug and profile kernel code.
> [...]

It may make sense to mention in addition that this version of
kmemtrace uses markers as the low-level hook mechanism, and this makes
the data generated directly accessible to other tracing tools such as
systemtap. Thank you!


- FChE

Subject: Re: [RFC PATCH 1/4] kmemtrace: Core implementation.

On Tue, Jul 22, 2008 at 05:28:16PM -0400, Frank Ch. Eigler wrote:
>
> Eduard - Gabriel Munteanu <[email protected]> writes:
>
> > kmemtrace provides tracing for slab allocator functions, such as kmalloc,
> > kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected data is then fed
> > to the userspace application in order to analyse allocation hotspots,
> > internal fragmentation and so on, making it possible to see how well an
> > allocator performs, as well as debug and profile kernel code.
> > [...]
>
> It may make sense to mention in addition that this version of
> kmemtrace uses markers as the low-level hook mechanism, and this makes
> the data generated directly accessible to other tracing tools such as
> systemtap. Thank you!
>
>
> - FChE

Sounds like a good idea, but I'd like to get rid of markers and use
Mathieu Desnoyers' tracepoints instead. I'm just waiting for tracepoints
to get closer to inclusion in mainline/-mm.

It would be great if tracepoints completely replaced markers, so SystemTap
would use those instead.

However, if tracepoints are not ready when kmemtrace is to be merged,
I'll take your advice and mention markers and SystemTap.


Thanks,
Eduard

Subject: Re: [RFC PATCH 1/4] kmemtrace: Core implementation.

On Wed, Jul 23, 2008 at 03:50:02AM +0300, Eduard - Gabriel Munteanu wrote:
> On Tue, Jul 22, 2008 at 05:28:16PM -0400, Frank Ch. Eigler wrote:
> >
> > Eduard - Gabriel Munteanu <[email protected]> writes:
> >
> > > kmemtrace provides tracing for slab allocator functions, such as kmalloc,
> > > kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected data is then fed
> > > to the userspace application in order to analyse allocation hotspots,
> > > internal fragmentation and so on, making it possible to see how well an
> > > allocator performs, as well as debug and profile kernel code.
> > > [...]
> >
> > It may make sense to mention in addition that this version of
> > kmemtrace uses markers as the low-level hook mechanism, and this makes
> > the data generated directly accessible to other tracing tools such as
> > systemtap. Thank you!
> >
> >
> > - FChE
>
> Sounds like a good idea, but I'd like to get rid of markers and use
> Mathieu Desnoyers' tracepoints instead. I'm just waiting for tracepoints
> to get closer to inclusion in mainline/-mm.
>
> It would be great if tracepoints completely replaced markers, so SystemTap
> would use those instead.
>
> However, if tracepoints are not ready when kmemtrace is to be merged,
> I'll take your advice and mention markers and SystemTap.
>
>
> Thanks,
> Eduard
>

(fixed Matt's Cc.)

2008-07-23 01:28:41

by Frank Ch. Eigler

[permalink] [raw]
Subject: Re: [RFC PATCH 1/4] kmemtrace: Core implementation.

Hi -


On Wed, Jul 23, 2008 at 03:50:02AM +0300, Eduard - Gabriel Munteanu wrote:

> [...] Sounds like a good idea, but I'd like to get rid of markers
> and use Mathieu Desnoyers' tracepoints instead. I'm just waiting for
> tracepoints to get closer to inclusion in mainline/-mm.

OK.

> It would be great if tracepoints completely replaced markers, so
> SystemTap would use those instead.

Raw tracepoints are problematic as they require a per-tracepoint C
function signature to be synthesized by the tool (or hard-coded in the
tool or elsewhere). We haven't worked out how best do to this. OTOH,
markers don't require such hard-coding, so are simpler for a general
tool to interface to.


> However, if tracepoints are not ready when kmemtrace is to be merged,
> I'll take your advice and mention markers and SystemTap.

Thanks either way - I'm glad you found an existing tracing mechanism
usable and didn't choose/need to invent your own.


- FChE