Re: [patch 2/8] 2.6.22-rc3 perfmon2 : Debug messages added

From: David Rientjes
Date: Wed Jun 20 2007 - 15:49:33 EST


On Wed, 20 Jun 2007, Robert Richter wrote:

> Debug messages added for better debugging.
>

And you added BUG_ON()'s.

> Signed-off-by: Robert Richter <robert.richter@xxxxxxx>
>
> Index: linux-2.6.22-rc3/perfmon/perfmon_file.c
> ===================================================================
> --- linux-2.6.22-rc3.orig/perfmon/perfmon_file.c
> +++ linux-2.6.22-rc3/perfmon/perfmon_file.c
> @@ -192,6 +192,8 @@ static int pfm_mmap(struct file *file, s
> unsigned long flags;
> int ret;
>
> + PFM_DBG("pfm_file_ops");

After commenting on your first set of patches, I've been using it a little
more. In my use, these debugging messages weren't very helpful because
"pfm_file_ops" can indicate pfm_mmap, pfm_read, pfm_poll, etc. Could
these be changed to be more specific based on the function they're in?

> Index: linux-2.6.22-rc3/perfmon/perfmon_syscalls.c
> ===================================================================
> --- linux-2.6.22-rc3.orig/perfmon/perfmon_syscalls.c
> +++ linux-2.6.22-rc3/perfmon/perfmon_syscalls.c
> @@ -403,6 +403,8 @@ asmlinkage long sys_pfm_create_context(s
> void *fmt_arg = NULL;
> int ret;
>
> + PFM_DBG("syscall");

Likewise. Using "syscall" for all debugging messages in the syscall
handlers isn't very informative. Could this be PFM_DBG(__FUNCTION__)
instead?

> +
> if (atomic_read(&perfmon_disabled))
> return -ENOSYS;
>
> @@ -433,8 +435,12 @@ asmlinkage long sys_pfm_write_pmcs(int f
> size_t sz;
> int ret, fput_needed;
>
> - if (count < 0 || count >= PFM_MAX_ARG_COUNT(ureq))
> + PFM_DBG("syscall");
> +
> + if (count < 0 || count >= PFM_MAX_ARG_COUNT(ureq)) {
> + PFM_DBG("invalid arg count %d", count);

This is whitespace damaged.

> return -EINVAL;
> + }
>
> sz = count*sizeof(*ureq);
>
> @@ -475,6 +481,8 @@ asmlinkage long sys_pfm_write_pmcs(int f
> kfree(fptr);
> error:
> fput_light(filp, fput_needed);
> + if (ret)
> + PFM_DBG("failed: errno=%d", -ret);

What failed? More information would be helpful since this is, after all,
a diagnostic message.

> Index: linux-2.6.22-rc3/include/asm-i386/perfmon.h
> ===================================================================
> --- linux-2.6.22-rc3.orig/include/asm-i386/perfmon.h
> +++ linux-2.6.22-rc3/include/asm-i386/perfmon.h
> @@ -140,6 +140,10 @@ static inline void pfm_arch_write_pmc(st
> if (ctx && ctx->flags.started == 0)
> return;
>
> + PFM_DBG_ovfl("pfm_arch_write_pmc(0x%016Lx, 0x%016Lx)",
> + (unsigned long long) pfm_pmu_conf->pmc_desc[cnum].hw_addr,
> + (unsigned long long) value);

Casting here should be unnecessary. Changing %L would be advisible to
display the data as it is stored in the object.

> + BUG_ON(pfm_pmu_conf->pmc_desc[cnum].type & PFM_REG_V);
> if (arch_info->pmu_style == PFM_X86_PMU_P4)
> __pfm_write_reg_p4(&arch_info->pmc_addrs[cnum], value);
> else
> @@ -155,6 +159,10 @@ static inline void pfm_arch_write_pmd(st
> if (pfm_pmu_conf->pmd_desc[cnum].type & PFM_REG_C64)
> value |= ~pfm_pmu_conf->ovfl_mask;
>
> + PFM_DBG_ovfl("pfm_arch_write_pmd(0x%016Lx, 0x%016Lx)",
> + (unsigned long long) pfm_pmu_conf->pmd_desc[cnum].hw_addr,
> + (unsigned long long) value);
> + BUG_ON(pfm_pmu_conf->pmd_desc[cnum].type & PFM_REG_V);
> if (arch_info->pmu_style == PFM_X86_PMU_P4)
> __pfm_write_reg_p4(&arch_info->pmd_addrs[cnum], value);
> else
> @@ -165,10 +173,14 @@ static inline u64 pfm_arch_read_pmd(stru
> {
> struct pfm_arch_pmu_info *arch_info = pfm_pmu_conf->arch_info;
> u64 tmp;
> + BUG_ON(pfm_pmu_conf->pmd_desc[cnum].type & PFM_REG_V);
> if (arch_info->pmu_style == PFM_X86_PMU_P4)
> __pfm_read_reg_p4(&arch_info->pmd_addrs[cnum], &tmp);
> else
> rdmsrl(pfm_pmu_conf->pmd_desc[cnum].hw_addr, tmp);
> + PFM_DBG_ovfl("pfm_arch_read_pmd(0x%016Lx) = 0x%016Lx",
> + (unsigned long long) pfm_pmu_conf->pmd_desc[cnum].hw_addr,
> + (unsigned long long) tmp);
> return tmp;
> }
>
> @@ -176,10 +188,14 @@ static inline u64 pfm_arch_read_pmc(stru
> {
> struct pfm_arch_pmu_info *arch_info = pfm_pmu_conf->arch_info;
> u64 tmp;
> + BUG_ON(pfm_pmu_conf->pmc_desc[cnum].type & PFM_REG_V);
> if (arch_info->pmu_style == PFM_X86_PMU_P4)
> __pfm_read_reg_p4(&arch_info->pmc_addrs[cnum], &tmp);
> else
> rdmsrl(pfm_pmu_conf->pmc_desc[cnum].hw_addr, tmp);
> + PFM_DBG_ovfl("pfm_arch_read_pmc(0x%016Lx) = 0x%016Lx",
> + (unsigned long long) pfm_pmu_conf->pmc_desc[cnum].hw_addr,
> + (unsigned long long) tmp);

More whitespace damage.
-
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