Commit 28db64fc authored by Peter Maydell's avatar Peter Maydell
Browse files

Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging 



Pull request

# gpg: Signature made Thu 30 Jan 2020 21:38:06 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  qemu_set_log_filename: filename argument may be NULL
  hw/display/qxl.c: Use trace_event_get_state_backends()
  memory.c: Use trace_event_get_state_backends()
  docs/devel/tracing.txt: Recommend only trace_event_get_state_backends()
  Makefile: Keep trace-events-subdirs ordered

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents aeab8e5e e144a605

Makefile.objs

+2 −2
Original line number Diff line number Diff line
@@ -132,8 +132,8 @@ trace-events-subdirs += nbd 
trace-events-subdirs += scsi

endif

ifeq ($(CONFIG_SOFTMMU),y)

trace-events-subdirs += chardev

trace-events-subdirs += audio

trace-events-subdirs += chardev

trace-events-subdirs += hw/9pfs

trace-events-subdirs += hw/acpi

trace-events-subdirs += hw/alpha
@@ -181,6 +181,7 @@ trace-events-subdirs += migration 
trace-events-subdirs += net

trace-events-subdirs += ui

endif

trace-events-subdirs += hw/core

trace-events-subdirs += hw/display

trace-events-subdirs += qapi

trace-events-subdirs += qom
@@ -193,7 +194,6 @@ trace-events-subdirs += target/riscv 
trace-events-subdirs += target/s390x

trace-events-subdirs += target/sparc

trace-events-subdirs += util

trace-events-subdirs += hw/core



trace-events-files = $(SRC_PATH)/trace-events $(trace-events-subdirs:%=$(SRC_PATH)/%/trace-events)

docs/devel/tracing.txt

+5 −7
Original line number Diff line number Diff line
@@ -342,8 +342,10 @@ edit the "trace-events-all" file). 


In addition, there might be cases where relatively complex computations must be

performed to generate values that are only used as arguments for a trace

function. In these cases you can use the macro 'TRACE_${EVENT_NAME}_ENABLED' to

guard such computations and avoid its compilation when the event is disabled:

function. In these cases you can use 'trace_event_get_state_backends()' to

guard such computations, so they are skipped if the event has been either

compile-time disabled or run-time disabled. If the event is compile-time

disabled, this check will have no performance impact.



    #include "trace.h"  /* needed for trace event prototype */
@@ -356,7 +358,7 @@ guard such computations and avoid its compilation when the event is disabled: 
            align = getpagesize();

        }

        ptr = qemu_memalign(align, size);

        if (TRACE_QEMU_VMALLOC_ENABLED) { /* preprocessor macro */

        if (trace_event_get_state_backends(TRACE_QEMU_VMALLOC)) {

            void *complex;

            /* some complex computations to produce the 'complex' value */

            trace_qemu_vmalloc(size, ptr, complex);
@@ -364,10 +366,6 @@ guard such computations and avoid its compilation when the event is disabled: 
        return ptr;

    }



You can check both if the event has been disabled and is dynamically enabled at

the same time using the 'trace_event_get_state_backends' routine (see header

"trace/control.h" for more information).



=== "tcg" ===



Guest code generated by TCG can be traced by defining an event with the "tcg"

hw/display/qxl.c

+1 −1
Original line number Diff line number Diff line
@@ -1764,7 +1764,7 @@ async_common: 
        qxl_set_mode(d, val, 0);

        break;

    case QXL_IO_LOG:

        if (TRACE_QXL_IO_LOG_ENABLED || d->guestdebug) {

        if (trace_event_get_state_backends(TRACE_QXL_IO_LOG) || d->guestdebug) {

            /* We cannot trust the guest to NUL terminate d->ram->log_buf */

            char *log_buf = g_strndup((const char *)d->ram->log_buf,

                                      sizeof(d->ram->log_buf));

memory.c

+4 −4
Original line number Diff line number Diff line
@@ -434,7 +434,7 @@ static MemTxResult memory_region_read_accessor(MemoryRegion *mr, 
    tmp = mr->ops->read(mr->opaque, addr, size);

    if (mr->subpage) {

        trace_memory_region_subpage_read(get_cpu_index(), mr, addr, tmp, size);

    } else if (TRACE_MEMORY_REGION_OPS_READ_ENABLED) {

    } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_READ)) {

        hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);

        trace_memory_region_ops_read(get_cpu_index(), mr, abs_addr, tmp, size);

    }
@@ -456,7 +456,7 @@ static MemTxResult memory_region_read_with_attrs_accessor(MemoryRegion *mr, 
    r = mr->ops->read_with_attrs(mr->opaque, addr, &tmp, size, attrs);

    if (mr->subpage) {

        trace_memory_region_subpage_read(get_cpu_index(), mr, addr, tmp, size);

    } else if (TRACE_MEMORY_REGION_OPS_READ_ENABLED) {

    } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_READ)) {

        hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);

        trace_memory_region_ops_read(get_cpu_index(), mr, abs_addr, tmp, size);

    }
@@ -476,7 +476,7 @@ static MemTxResult memory_region_write_accessor(MemoryRegion *mr, 


    if (mr->subpage) {

        trace_memory_region_subpage_write(get_cpu_index(), mr, addr, tmp, size);

    } else if (TRACE_MEMORY_REGION_OPS_WRITE_ENABLED) {

    } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_WRITE)) {

        hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);

        trace_memory_region_ops_write(get_cpu_index(), mr, abs_addr, tmp, size);

    }
@@ -496,7 +496,7 @@ static MemTxResult memory_region_write_with_attrs_accessor(MemoryRegion *mr, 


    if (mr->subpage) {

        trace_memory_region_subpage_write(get_cpu_index(), mr, addr, tmp, size);

    } else if (TRACE_MEMORY_REGION_OPS_WRITE_ENABLED) {

    } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_WRITE)) {

        hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);

        trace_memory_region_ops_write(get_cpu_index(), mr, abs_addr, tmp, size);

    }

trace/control.c

+1 −3
Original line number Diff line number Diff line
@@ -229,9 +229,7 @@ void trace_init_file(const char *file) 
    /* If both the simple and the log backends are enabled, "--trace file"

     * only applies to the simple backend; use "-D" for the log backend.

     */

    if (file) {

    qemu_set_log_filename(file, &error_fatal);

    }

#else

    if (file) {

        fprintf(stderr, "error: --trace file=...: "