vandersonmr <vanderson...@gmail.com> writes:
> To store statistics for each TB, we created a TBStatistics structure
> which is linked with the TBs. TBStatistics can stay alive after
> tb_flush and be relinked to a regenerated TB. So the statistics can
> be accumulated even through flushes.
>
> The goal is to have all present and future qemu/tcg statistics and
> meta-data stored in this new structure.
>
> Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
> Signed-off-by: Vanderson M. do Rosario <vanderson...@gmail.com>
> ---
> accel/tcg/Makefile.objs | 2 +-
> accel/tcg/tb-stats.c | 63 ++++++++++++++++++++++++++++++++++++
> accel/tcg/translate-all.c | 57 +++++++++++++++++++++++++++++++++
> include/exec/exec-all.h | 15 +++------
> include/exec/tb-context.h | 12 +++++++
> include/exec/tb-hash.h | 7 ++++
> include/exec/tb-stats.h | 67 +++++++++++++++++++++++++++++++++++++++
> util/log.c | 2 ++
> 8 files changed, 213 insertions(+), 12 deletions(-)
> create mode 100644 accel/tcg/tb-stats.c
> create mode 100644 include/exec/tb-stats.h
>
> diff --git a/accel/tcg/Makefile.objs b/accel/tcg/Makefile.objs
> index d381a02f34..49ffe81b5d 100644
> --- a/accel/tcg/Makefile.objs
> +++ b/accel/tcg/Makefile.objs
> @@ -2,7 +2,7 @@ obj-$(CONFIG_SOFTMMU) += tcg-all.o
> obj-$(CONFIG_SOFTMMU) += cputlb.o
> obj-y += tcg-runtime.o tcg-runtime-gvec.o
> obj-y += cpu-exec.o cpu-exec-common.o translate-all.o
> -obj-y += translator.o
> +obj-y += translator.o tb-stats.o
>
> obj-$(CONFIG_USER_ONLY) += user-exec.o
> obj-$(call lnot,$(CONFIG_SOFTMMU)) += user-exec-stub.o
> diff --git a/accel/tcg/tb-stats.c b/accel/tcg/tb-stats.c
> new file mode 100644
> index 0000000000..948b107e68
> --- /dev/null
> +++ b/accel/tcg/tb-stats.c
> @@ -0,0 +1,63 @@
> +/*
> + * QEMU System Emulator, Code Quality Monitor System
> + *
> + * Copyright (c) 2019 Vanderson M. do Rosario <vanderson...@gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> copy
> + * of this software and associated documentation files (the "Software"), to
> deal
> + * in the Software without restriction, including without limitation the
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "qemu/osdep.h"
> +
> +#include "disas/disas.h"
> +
> +#include "exec/tb-stats.h"
> +
> +void init_tb_stats_htable_if_not(void)
> +{
> + if (tb_stats_collection_enabled() && !tb_ctx.tb_stats.map) {
> + qht_init(&tb_ctx.tb_stats, tb_stats_cmp,
> + CODE_GEN_HTABLE_SIZE, QHT_MODE_AUTO_RESIZE);
> + }
> +}
> +
> +void enable_collect_tb_stats(void)
> +{
> + init_tb_stats_htable_if_not();
> + tcg_collect_tb_stats = TB_STATS_RUNNING;
> +}
> +
> +void disable_collect_tb_stats(void)
> +{
> + tcg_collect_tb_stats = TB_STATS_PAUSED;
> +}
> +
> +void pause_collect_tb_stats(void)
> +{
> + tcg_collect_tb_stats = TB_STATS_STOPPED;
> +}
> +
> +bool tb_stats_collection_enabled(void)
> +{
> + return tcg_collect_tb_stats == TB_STATS_RUNNING;
> +}
> +
> +bool tb_stats_collection_paused(void)
> +{
> + return tcg_collect_tb_stats == TB_STATS_PAUSED;
> +}
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index 5d1e08b169..b7bccacd3b 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1118,6 +1118,23 @@ static inline void code_gen_alloc(size_t tb_size)
> }
> }
>
> +/*
> + * This is the more or less the same compare as tb_cmp(), but the
> + * data persists over tb_flush. We also aggregate the various
> + * variations of cflags under one record and ignore the details of
> + * page overlap (although we can count it).
> + */
> +bool tb_stats_cmp(const void *ap, const void *bp)
> +{
> + const TBStatistics *a = ap;
> + const TBStatistics *b = bp;
> +
> + return a->phys_pc == b->phys_pc &&
> + a->pc == b->pc &&
> + a->cs_base == b->cs_base &&
> + a->flags == b->flags;
> +}
> +
> static bool tb_cmp(const void *ap, const void *bp)
> {
> const TranslationBlock *a = ap;
> @@ -1137,6 +1154,7 @@ static void tb_htable_init(void)
> unsigned int mode = QHT_MODE_AUTO_RESIZE;
>
> qht_init(&tb_ctx.htable, tb_cmp, CODE_GEN_HTABLE_SIZE, mode);
> + init_tb_stats_htable_if_not();
> }
>
> /* Must be called before using the QEMU cpus. 'tb_size' is the size
> @@ -1666,6 +1684,34 @@ tb_link_page(TranslationBlock *tb, tb_page_addr_t
> phys_pc,
> return tb;
> }
>
> +static TBStatistics *tb_get_stats(tb_page_addr_t phys_pc, target_ulong pc,
> + target_ulong cs_base, uint32_t flags,
> + TranslationBlock *current_tb)
> +{
> + TBStatistics *new_stats = g_new0(TBStatistics, 1);
> + uint32_t hash = tb_stats_hash_func(phys_pc, pc, flags);
> + void *existing_stats = NULL;
> + new_stats->phys_pc = phys_pc;
> + new_stats->pc = pc;
> + new_stats->cs_base = cs_base;
> + new_stats->flags = flags;
> + new_stats->tb = current_tb;
Drop the current_tb and the field from TBStatistics - it's not used by
anything else in this patch. Also see bellow:
> +
> + qht_insert(&tb_ctx.tb_stats, new_stats, hash, &existing_stats);
> +
> + if (unlikely(existing_stats)) {
> + /*
> + * If there is already a TBStatistic for this TB from a previous
> flush
> + * then just make the new TB point to the older TBStatistic
> + */
> + g_free(new_stats);
> + return existing_stats;
> + } else {
> + return new_stats;
> + }
> +}
> +
> +
> /* Called with mmap_lock held for user mode emulation. */
> TranslationBlock *tb_gen_code(CPUState *cpu,
> target_ulong pc, target_ulong cs_base,
> @@ -1732,6 +1778,17 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
> ti = profile_getclock();
> #endif
>
> + /*
> + * We want to fetch the stats structure before we start code
> + * generation so we can count interesting things about this
> + * generation.
> + */
> + if (tb_stats_collection_enabled()) {
> + tb->tb_stats = tb_get_stats(phys_pc, pc, cs_base, flags, tb);
> + } else {
> + tb->tb_stats = NULL;
> + }
> +
> tcg_func_start(tcg_ctx);
>
> tcg_ctx->cpu = env_cpu(env);
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index 135aeaab0d..1e0bd4e147 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -23,21 +23,11 @@
> #include "cpu.h"
> #include "exec/tb-context.h"
> #include "sysemu/cpus.h"
> +#include "exec/tb-stats.h"
>
> /* allow to see translation results - the slowdown should be negligible, so
> we leave it */
> #define DEBUG_DISAS
>
> -/* Page tracking code uses ram addresses in system mode, and virtual
> - addresses in userspace mode. Define tb_page_addr_t to be an appropriate
> - type. */
> -#if defined(CONFIG_USER_ONLY)
> -typedef abi_ulong tb_page_addr_t;
> -#define TB_PAGE_ADDR_FMT TARGET_ABI_FMT_lx
> -#else
> -typedef ram_addr_t tb_page_addr_t;
> -#define TB_PAGE_ADDR_FMT RAM_ADDR_FMT
> -#endif
> -
> #include "qemu/log.h"
>
> void gen_intermediate_code(CPUState *cpu, TranslationBlock *tb, int
> max_insns);
> @@ -404,6 +394,9 @@ struct TranslationBlock {
> uintptr_t jmp_list_head;
> uintptr_t jmp_list_next[2];
> uintptr_t jmp_dest[2];
> +
> + /* Pointer to a struct where statistics from the TB is stored */
> + TBStatistics *tb_stats;
> };
>
> extern bool parallel_cpus;
> diff --git a/include/exec/tb-context.h b/include/exec/tb-context.h
> index feb585e0a7..3cfb62a338 100644
> --- a/include/exec/tb-context.h
> +++ b/include/exec/tb-context.h
> @@ -23,6 +23,17 @@
> #include "qemu/thread.h"
> #include "qemu/qht.h"
>
> +/* Page tracking code uses ram addresses in system mode, and virtual
> + addresses in userspace mode. Define tb_page_addr_t to be an appropriate
> + type. */
> +#if defined(CONFIG_USER_ONLY)
> +typedef abi_ulong tb_page_addr_t;
> +#define TB_PAGE_ADDR_FMT TARGET_ABI_FMT_lx
> +#else
> +typedef ram_addr_t tb_page_addr_t;
> +#define TB_PAGE_ADDR_FMT RAM_ADDR_FMT
> +#endif
> +
> #define CODE_GEN_HTABLE_BITS 15
> #define CODE_GEN_HTABLE_SIZE (1 << CODE_GEN_HTABLE_BITS)
>
> @@ -35,6 +46,7 @@ struct TBContext {
>
> /* statistics */
> unsigned tb_flush_count;
> + struct qht tb_stats;
> };
>
> extern TBContext tb_ctx;
> diff --git a/include/exec/tb-hash.h b/include/exec/tb-hash.h
> index 805235d321..dd8e8f252a 100644
> --- a/include/exec/tb-hash.h
> +++ b/include/exec/tb-hash.h
> @@ -66,4 +66,11 @@ uint32_t tb_hash_func(tb_page_addr_t phys_pc, target_ulong
> pc, uint32_t flags,
> return qemu_xxhash7(phys_pc, pc, flags, cf_mask, trace_vcpu_dstate);
> }
>
> +static inline
> +uint32_t tb_stats_hash_func(tb_page_addr_t phys_pc, target_ulong pc,
> + uint32_t flags)
> +{
> + return qemu_xxhash5(phys_pc, pc, flags);
> +}
> +
> #endif
> diff --git a/include/exec/tb-stats.h b/include/exec/tb-stats.h
> new file mode 100644
> index 0000000000..898e05a36f
> --- /dev/null
> +++ b/include/exec/tb-stats.h
> @@ -0,0 +1,67 @@
> +/*
> + * QEMU System Emulator, Code Quality Monitor System
> + *
> + * Copyright (c) 2019 Vanderson M. do Rosario <vanderson...@gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> copy
> + * of this software and associated documentation files (the "Software"), to
> deal
> + * in the Software without restriction, including without limitation the
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef TB_STATS_H
> +
> +#define TB_STATS_H
> +
> +#include "exec/cpu-common.h"
> +#include "exec/tb-context.h"
> +#include "tcg.h"
> +
> +typedef struct TBStatistics TBStatistics;
> +
> +/*
> + * This struct stores statistics such as execution count of the
> + * TranslationBlocks. Each sets of TBs for a given phys_pc/pc/flags
> + * has its own TBStatistics which will persist over tb_flush.
> + *
> + * We include additional counters to track number of translations as
> + * well as variants for compile flags.
> + */
> +struct TBStatistics {
> + tb_page_addr_t phys_pc;
> + target_ulong pc;
> + uint32_t flags;
> + /* cs_base isn't included in the hash but we do check for matches */
> + target_ulong cs_base;
> + /* current TB linked to this TBStatistics */
> + TranslationBlock *tb;
This seems sketchy to me. The TBStats have a 1 to many relationship so
I'm not sure what this information can be used for.
> +};
> +
> +bool tb_stats_cmp(const void *ap, const void *bp);
> +
> +void init_tb_stats_htable_if_not(void);
> +
> +/* TBStatistic collection controls */
> +enum TBStatsStatus { TB_STATS_RUNNING, TB_STATS_PAUSED, TB_STATS_STOPPED };
> +extern int tcg_collect_tb_stats;
> +
> +void enable_collect_tb_stats(void);
> +void disable_collect_tb_stats(void);
> +void pause_collect_tb_stats(void);
> +bool tb_stats_collection_enabled(void);
> +bool tb_stats_collection_paused(void);
> +
> +#endif
> diff --git a/util/log.c b/util/log.c
> index 1d1b33f7d9..393a17115b 100644
> --- a/util/log.c
> +++ b/util/log.c
> @@ -31,6 +31,8 @@ int qemu_loglevel;
> static int log_append = 0;
> static GArray *debug_regions;
>
> +int tcg_collect_tb_stats;
> +
> /* Return the number of characters emitted. */
> int qemu_log(const char *fmt, ...)
> {
--
Alex Bennée
