* [PATCH v3] plugins/syscall: Added a table-like summary output
@ 2021-04-20 11:54 Mahmoud Mandour
2021-05-05 13:13 ` Alex Bennée
0 siblings, 1 reply; 3+ messages in thread
From: Mahmoud Mandour @ 2021-04-20 11:54 UTC (permalink / raw)
To: qemu-devel; +Cc: Mahmoud Mandour, Alex Bennée
Added a table-like output which contains the total number of calls
for each used syscall along with the number of errors that occurred.
Per-call tracing is still available through supplying the argument
``print`` to the plugin.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
---
v2 -> v3: * Locked shared hash-table to protect access across multiple
callback invocations.
* Used better variable names for the hash table and entries.
* Factored the creation and looking-up for hash table entries.
* Eliminated the usage of a global boolean and checked against
the existence of the ``statistics`` hash-table. (it's allocated
only if the plugin in the summary(default) mode.
* Removed the function ``free_entry`` and passed ``g_free``
directly to ``g_hash_table_new_full()``.
tests/plugin/syscall.c | 98 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 93 insertions(+), 5 deletions(-)
diff --git a/tests/plugin/syscall.c b/tests/plugin/syscall.c
index 53ee2ab6c4..7b856f2fe2 100644
--- a/tests/plugin/syscall.c
+++ b/tests/plugin/syscall.c
@@ -16,32 +16,120 @@
QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
+typedef struct {
+ int64_t num;
+ int64_t calls;
+ int64_t errors;
+} SyscallStats;
+
+static GMutex lock;
+static GHashTable *statistics;
+
+static SyscallStats *get_or_create_entry(int64_t num)
+{
+ SyscallStats *entry =
+ (SyscallStats *) g_hash_table_lookup(statistics, GINT_TO_POINTER(num));
+
+ if (!entry) {
+ entry = g_new0(SyscallStats, 1);
+ entry->num = num;
+ g_hash_table_insert(statistics, GINT_TO_POINTER(num), (gpointer) entry);
+ }
+
+ return entry;
+}
+
static void vcpu_syscall(qemu_plugin_id_t id, unsigned int vcpu_index,
int64_t num, uint64_t a1, uint64_t a2,
uint64_t a3, uint64_t a4, uint64_t a5,
uint64_t a6, uint64_t a7, uint64_t a8)
{
- g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n", num);
- qemu_plugin_outs(out);
+ if (statistics) {
+ SyscallStats *entry;
+ g_mutex_lock(&lock);
+ entry = get_or_create_entry(num);
+ entry->calls++;
+ g_mutex_unlock(&lock);
+ } else {
+ g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n", num);
+ qemu_plugin_outs(out);
+ }
}
static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned int vcpu_idx,
int64_t num, int64_t ret)
+{
+ if (statistics) {
+ SyscallStats *entry;
+
+ g_mutex_lock(&lock);
+ /* Should always return an existent entry. */
+ entry = get_or_create_entry(num);
+ if (ret < 0) {
+ entry->errors++;
+ }
+ g_mutex_unlock(&lock);
+ } else {
+ g_autofree gchar *out;
+ out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
+ num, ret);
+ qemu_plugin_outs(out);
+ }
+}
+
+void print_entry(gpointer val, gpointer user_data)
{
g_autofree gchar *out;
- out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
- num, ret);
+ SyscallStats *entry = (SyscallStats *) val;
+ int64_t syscall_num = entry->num;
+ out = g_strdup_printf(
+ "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
+ syscall_num, entry->calls, entry->errors);
qemu_plugin_outs(out);
}
+static gint comp_func(gconstpointer ea, gconstpointer eb)
+{
+ SyscallStats *ent_a = (SyscallStats *) ea;
+ SyscallStats *ent_b = (SyscallStats *) eb;
+
+ return ent_a->calls > ent_b->calls ? -1 : 1;
+}
+
/* ************************************************************************* */
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+ if (!statistics) {
+ return;
+ }
+
+ g_mutex_lock(&lock);
+ GList *entries = g_hash_table_get_values(statistics);
+ entries = g_list_sort(entries, comp_func);
+ qemu_plugin_outs("syscall no. calls errors\n");
-static void plugin_exit(qemu_plugin_id_t id, void *p) {}
+ g_list_foreach(entries, print_entry, NULL);
+
+ g_list_free(entries);
+ g_hash_table_destroy(statistics);
+ g_mutex_unlock(&lock);
+}
QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
const qemu_info_t *info,
int argc, char **argv)
{
+ if (argc == 0) {
+ statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL, g_free);
+ } else {
+ for (int i = 0; i < argc; i++) {
+ if (g_strcmp0(argv[i], "print") != 0) {
+ fprintf(stderr, "unsupported argument: %s\n", argv[i]);
+ return -1;
+ }
+ }
+ }
+
qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3] plugins/syscall: Added a table-like summary output
2021-04-20 11:54 [PATCH v3] plugins/syscall: Added a table-like summary output Mahmoud Mandour
@ 2021-05-05 13:13 ` Alex Bennée
2021-05-05 17:56 ` Mahmoud Mandour
0 siblings, 1 reply; 3+ messages in thread
From: Alex Bennée @ 2021-05-05 13:13 UTC (permalink / raw)
To: Mahmoud Mandour; +Cc: qemu-devel
Mahmoud Mandour <ma.mandourr@gmail.com> writes:
> Added a table-like output which contains the total number of calls
> for each used syscall along with the number of errors that occurred.
>
> Per-call tracing is still available through supplying the argument
> ``print`` to the plugin.
>
> Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
> ---
<snip>
> +
> +void print_entry(gpointer val, gpointer user_data)
> {
> g_autofree gchar *out;
> - out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
> - num, ret);
> + SyscallStats *entry = (SyscallStats *) val;
> + int64_t syscall_num = entry->num;
> + out = g_strdup_printf(
> + "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
> + syscall_num, entry->calls, entry->errors);
> qemu_plugin_outs(out);
> }
This still fails to compile due to a missing static:
[2/10] Compiling C object tests/plugin/libsyscall.so.p/syscall.c.o
FAILED: tests/plugin/libsyscall.so.p/syscall.c.o
cc -Itests/plugin/libsyscall.so.p -Itests/plugin -I../../tests/plugin -I../../include/qemu -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem /home/alex/lsrc/qemu.git/linux-headers -isystem linux-headers -iquote . -iquote /home/alex/lsrc/qemu.git -iquote /home/alex/lsrc/qemu.git/include -iquote /home/alex/lsrc/qemu.git/disas/libvixl -iquote /home/alex/lsrc/qemu.git/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -mcx16 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -DLEGACY_RDMA_REG_MR -fPIC -MD -MQ tests/plugin/libsyscall.so.p/syscall.c.o -MF tests/plugin/libsyscall.so.p/syscall.c.o.d -o tests/plugin/libsyscall.so.p/syscall.c.o -c ../../tests/plugin/syscall.c
../../tests/plugin/syscall.c:80:6: error: no previous prototype for ‘print_entry’ [-Werror=missing-prototypes]
void print_entry(gpointer val, gpointer user_data)
^~~~~~~~~~~
cc1: all warnings being treated as errors
ninja: build stopped: subcommand failed.
make: *** [Makefile:152: run-ninja] Error 1
>
> +static gint comp_func(gconstpointer ea, gconstpointer eb)
> +{
> + SyscallStats *ent_a = (SyscallStats *) ea;
> + SyscallStats *ent_b = (SyscallStats *) eb;
> +
> + return ent_a->calls > ent_b->calls ? -1 : 1;
> +}
> +
> /* ************************************************************************* */
> +static void plugin_exit(qemu_plugin_id_t id, void *p)
> +{
> + if (!statistics) {
> + return;
> + }
> +
> + g_mutex_lock(&lock);
> + GList *entries = g_hash_table_get_values(statistics);
> + entries = g_list_sort(entries, comp_func);
> + qemu_plugin_outs("syscall no. calls errors\n");
>
> -static void plugin_exit(qemu_plugin_id_t id, void *p) {}
> + g_list_foreach(entries, print_entry, NULL);
> +
> + g_list_free(entries);
> + g_hash_table_destroy(statistics);
> + g_mutex_unlock(&lock);
> +}
Hmm it looks like we see multiple plugin_exit's when running multiple
threads:
./qemu-aarch64 -d plugin -D output -plugin ./tests/plugin/libsyscall.so ./tests/tcg/aarch64-linux-user/linux-test
I don't see it with testthread or the new signals test though which is
confusing. Something linux-test is doing must be different.
>
> QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
> const qemu_info_t *info,
> int argc, char **argv)
> {
> + if (argc == 0) {
> + statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL, g_free);
> + } else {
> + for (int i = 0; i < argc; i++) {
> + if (g_strcmp0(argv[i], "print") != 0) {
> + fprintf(stderr, "unsupported argument: %s\n", argv[i]);
> + return -1;
> + }
> + }
> + }
> +
> qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
> qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
> qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
Otherwise looking pretty good - certainly a more useful default ;-)
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
--
Alex Bennée
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] plugins/syscall: Added a table-like summary output
2021-05-05 13:13 ` Alex Bennée
@ 2021-05-05 17:56 ` Mahmoud Mandour
0 siblings, 0 replies; 3+ messages in thread
From: Mahmoud Mandour @ 2021-05-05 17:56 UTC (permalink / raw)
To: Alex Bennée; +Cc: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 5504 bytes --]
On Wed, May 5, 2021 at 3:19 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>
> Mahmoud Mandour <ma.mandourr@gmail.com> writes:
>
> > Added a table-like output which contains the total number of calls
> > for each used syscall along with the number of errors that occurred.
> >
> > Per-call tracing is still available through supplying the argument
> > ``print`` to the plugin.
> >
> > Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
> > ---
> <snip>
> > +
> > +void print_entry(gpointer val, gpointer user_data)
> > {
> > g_autofree gchar *out;
> > - out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64
> "\n",
> > - num, ret);
> > + SyscallStats *entry = (SyscallStats *) val;
> > + int64_t syscall_num = entry->num;
> > + out = g_strdup_printf(
> > + "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
> > + syscall_num, entry->calls, entry->errors);
> > qemu_plugin_outs(out);
> > }
>
> This still fails to compile due to a missing static:
>
> [2/10] Compiling C object tests/plugin/libsyscall.so.p/syscall.c.o
> FAILED: tests/plugin/libsyscall.so.p/syscall.c.o
> cc -Itests/plugin/libsyscall.so.p -Itests/plugin -I../../tests/plugin
> -I../../include/qemu -I/usr/include/glib-2.0
> -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -fdiagnostics-color=auto -pipe
> -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem
> /home/alex/lsrc/qemu.git/linux-headers -isystem linux-headers -iquote .
> -iquote /home/alex/lsrc/qemu.git -iquote /home/alex/lsrc/qemu.git/include
> -iquote /home/alex/lsrc/qemu.git/disas/libvixl -iquote
> /home/alex/lsrc/qemu.git/tcg/i386 -pthread -U_FORTIFY_SOURCE
> -D_FORTIFY_SOURCE=2 -m64 -mcx16 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef
> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common
> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits
> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers
> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined
> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs
> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong
> -DLEGACY_RDMA_REG_MR -fPIC -MD -MQ tests/plugin/libsyscall.so.p/syscall.c.o
> -MF tests/plugin/libsyscall.so.p/syscall.c.o.d -o
> tests/plugin/libsyscall.so.p/syscall.c.o -c ../../tests/plugin/syscall.c
> ../../tests/plugin/syscall.c:80:6: error: no previous prototype for
> ‘print_entry’ [-Werror=missing-prototypes]
> void print_entry(gpointer val, gpointer user_data)
> ^~~~~~~~~~~
> cc1: all warnings being treated as errors
> ninja: build stopped: subcommand failed.
> make: *** [Makefile:152: run-ninja] Error 1
>
> Thanks for the notice. I got it working because I was building it using
the makefile in the
contrib/plugins makefile and it does not report warnings. I fixed it.
> >
> > +static gint comp_func(gconstpointer ea, gconstpointer eb)
> > +{
> > + SyscallStats *ent_a = (SyscallStats *) ea;
> > + SyscallStats *ent_b = (SyscallStats *) eb;
> > +
> > + return ent_a->calls > ent_b->calls ? -1 : 1;
> > +}
> > +
> > /*
> ************************************************************************* */
> > +static void plugin_exit(qemu_plugin_id_t id, void *p)
> > +{
> > + if (!statistics) {
> > + return;
> > + }
> > +
> > + g_mutex_lock(&lock);
> > + GList *entries = g_hash_table_get_values(statistics);
> > + entries = g_list_sort(entries, comp_func);
> > + qemu_plugin_outs("syscall no. calls errors\n");
> >
> > -static void plugin_exit(qemu_plugin_id_t id, void *p) {}
> > + g_list_foreach(entries, print_entry, NULL);
> > +
> > + g_list_free(entries);
> > + g_hash_table_destroy(statistics);
> > + g_mutex_unlock(&lock);
> > +}
>
> Hmm it looks like we see multiple plugin_exit's when running multiple
> threads:
>
> ./qemu-aarch64 -d plugin -D output -plugin ./tests/plugin/libsyscall.so
> ./tests/tcg/aarch64-linux-user/linux-test
>
> I don't see it with testthread or the new signals test though which is
> confusing. Something linux-test is doing must be different.
>
The output of other plugins is similar so apparently there's something
different with linux-test, yes.
Since this is not a bug related to this particular patch, should I fix the
compilation error and resend the patch?
>
> >
> > QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
> > const qemu_info_t *info,
> > int argc, char **argv)
> > {
> > + if (argc == 0) {
> > + statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL,
> g_free);
> > + } else {
> > + for (int i = 0; i < argc; i++) {
> > + if (g_strcmp0(argv[i], "print") != 0) {
> > + fprintf(stderr, "unsupported argument: %s\n", argv[i]);
> > + return -1;
> > + }
> > + }
> > + }
> > +
> > qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
> > qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
> > qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
>
> Otherwise looking pretty good - certainly a more useful default ;-)
>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
>
>
> --
> Alex Bennée
>
Thanks,
Mahmoud
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2021-04-20 11:54 [PATCH v3] plugins/syscall: Added a table-like summary output Mahmoud Mandour
2021-05-05 13:13 ` Alex Bennée
2021-05-05 17:56 ` Mahmoud Mandour
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