Re: [Qemu-trivial] [PATCH v4 11/11] cputlb: modernise the debug support

[Aurelien Jarno]

On 2015-08-03 10:14, Alex Bennée wrote:
> To avoid cluttering the code with #ifdef legs we wrap up the print
> statements into a tlb_debug() macro. As access to the virtual TLB can
> get quite heavy defining DEBUG_TLB_LOG will ensure all the logs go to
> the qemu_log target of CPU_LOG_MMU instead of stderr.
> 
> I've also removed DEBUG_TLB_CHECK which wasn't used.
> 
> Signed-off-by: Alex Bennée <address@hidden>
> 
> ---
> v2
>   - ensure the compiler checks format strings even if debug is optimised out
> ---
>  cputlb.c | 54 +++++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 35 insertions(+), 19 deletions(-)
> 
> diff --git a/cputlb.c b/cputlb.c
> index a506086..7095e6f 100644
> --- a/cputlb.c
> +++ b/cputlb.c
> @@ -30,8 +30,30 @@
>  #include "exec/ram_addr.h"
>  #include "tcg/tcg.h"
>  
> -//#define DEBUG_TLB
> -//#define DEBUG_TLB_CHECK
> +/* DEBUG defines, enable DEBUG_TLB_LOG to log to the CPU_LOG_MMU target */
> +/* #define DEBUG_TLB */
> +/* #define DEBUG_TLB_LOG */
> +
> +#ifdef DEBUG_TLB
> +# define DEBUG_TLB_GATE 1
> +# ifdef DEBUG_TLB_LOG
> +#  define DEBUG_TLB_LOG_GATE 1
> +# else
> +#  define DEBUG_TLB_LOG_GATE 0
> +# endif
> +#else
> +# define DEBUG_TLB_GATE 0
> +# define DEBUG_TLB_LOG_GATE 0
> +#endif
> +
> +#define tlb_debug(fmt, ...) do { \
> +    if (DEBUG_TLB_LOG_GATE) { \
> +        qemu_log_mask(CPU_LOG_MMU, "%s: " fmt, __func__, \
> +                      ## __VA_ARGS__); \
> +    } else if (DEBUG_TLB_GATE) { \
> +        fprintf(stderr, "%s: " fmt, __func__, ## __VA_ARGS__); \
> +    } \
> +} while (0)

Do we really want to support sending debug logs to either the logfile or
stderr? It's already possible to send the debug logs through stderr when
not specifying -D file.

>  /* statistics */
>  int tlb_flush_count;
> @@ -52,9 +74,8 @@ void tlb_flush(CPUState *cpu, int flush_global)
>  {
>      CPUArchState *env = cpu->env_ptr;
>  
> -#if defined(DEBUG_TLB)
> -    printf("tlb_flush:\n");
> -#endif
> +    tlb_debug("(%d)\n", flush_global);
> +
>      /* must reset current TB so that interrupts cannot modify the
>         links while we are modifying them */
>      cpu->current_tb = NULL;
> @@ -87,16 +108,14 @@ void tlb_flush_page(CPUState *cpu, target_ulong addr)
>      int i;
>      int mmu_idx;
>  
> -#if defined(DEBUG_TLB)
> -    printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr);
> -#endif
> +    tlb_debug("page :" TARGET_FMT_lx "\n", addr);
> +
>      /* Check if we need to flush due to large pages.  */
>      if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
> -#if defined(DEBUG_TLB)
> -        printf("tlb_flush_page: forced full flush ("
> -               TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
> -               env->tlb_flush_addr, env->tlb_flush_mask);
> -#endif
> +        tlb_debug("forcing full flush ("
> +                  TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
> +                  env->tlb_flush_addr, env->tlb_flush_mask);
> +
>          tlb_flush(cpu, 1);
>          return;
>      }
> @@ -271,12 +290,9 @@ void tlb_set_page_with_attrs(CPUState *cpu, target_ulong 
> vaddr,
>      section = address_space_translate_for_iotlb(cpu, paddr, &xlat, &sz);
>      assert(sz >= TARGET_PAGE_SIZE);
>  
> -#if defined(DEBUG_TLB)
> -    qemu_log_mask(CPU_LOG_MMU,
> -           "tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
> -           " prot=%x idx=%d\n",
> -           vaddr, paddr, prot, mmu_idx);
> -#endif
> +    tlb_debug("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
> +              " prot=%x idx=%d\n",
> +              vaddr, paddr, prot, mmu_idx);
>  
>      address = vaddr;
>      if (!memory_region_is_ram(section->mr) && 
> !memory_region_is_romd(section->mr)) {
> -- 
> 2.5.0
> 
> 

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
address@hidden                 http://www.aurel32.net