Subject: Re: [PATCH v2 11/11] powerpc/mm: drop slice DEBUG

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Fri, 26 Apr 2019 12:14:39 +0530

Christophe Leroy <[email-masked]> writes:

> slice is now an improved functionnality. Drop the DEBUG stuff.
>

I would like to keep that. I helped a lot when moving address ranges and
it should not have any runtime impact.

> Signed-off-by: Christophe Leroy <[email-masked]>
> ---
>  arch/powerpc/mm/slice.c | 62 ++++---------------------------------------------
>  1 file changed, 4 insertions(+), 58 deletions(-)
>
> diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
> index 97fbf7b54422..a9d803738b65 100644
> --- a/arch/powerpc/mm/slice.c
> +++ b/arch/powerpc/mm/slice.c
> @@ -41,28 +41,6 @@
>  
>  static DEFINE_SPINLOCK(slice_convert_lock);
>  
> -#ifdef DEBUG
> -int _slice_debug = 1;
> -
> -static void slice_print_mask(const char *label, const struct slice_mask *mask)
> -{
> -	if (!_slice_debug)
> -		return;
> -	pr_devel("%s low_slice: %*pbl\n", label,
> -			(int)SLICE_NUM_LOW, &mask->low_slices);
> -	pr_devel("%s high_slice: %*pbl\n", label,
> -			(int)SLICE_NUM_HIGH, mask->high_slices);
> -}
> -
> -#define slice_dbg(fmt...) do { if (_slice_debug) pr_devel(fmt); } while (0)
> -
> -#else
> -
> -static void slice_print_mask(const char *label, const struct slice_mask *mask) {}
> -#define slice_dbg(fmt...)
> -
> -#endif
> -
>  static inline bool slice_addr_is_low(unsigned long addr)
>  {
>  	u64 tmp = (u64)addr;
> @@ -207,9 +185,6 @@ static void slice_convert(struct mm_struct *mm,
>  	unsigned long i, flags;
>  	int old_psize;
>  
> -	slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
> -	slice_print_mask(" mask", mask);
> -
>  	psize_mask = slice_mask_for_size(&mm->context, psize);
>  
>  	/* We need to use a spinlock here to protect against
> @@ -255,10 +230,6 @@ static void slice_convert(struct mm_struct *mm,
>  				(((unsigned long)psize) << (mask_index * 4));
>  	}
>  
> -	slice_dbg(" lsps=%lx, hsps=%lx\n",
> -		  (unsigned long)mm_ctx_low_slices(&mm->context),
> -		  (unsigned long)mm_ctx_high_slices(&mm->context));
> -
>  	spin_unlock_irqrestore(&slice_convert_lock, flags);
>  
>  	copro_flush_all_slbs(mm);
> @@ -485,14 +456,9 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  	BUG_ON(mm_ctx_slb_addr_limit(&mm->context) == 0);
>  	VM_BUG_ON(radix_enabled());
>  
> -	slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
> -	slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n",
> -		  addr, len, flags, topdown);
> -
>  	/* If hint, make sure it matches our alignment restrictions */
>  	if (!fixed && addr) {
>  		addr = _ALIGN_UP(addr, page_size);
> -		slice_dbg(" aligned addr=%lx\n", addr);
>  		/* Ignore hint if it's too large or overlaps a VMA */
>  		if (addr > high_limit - len || addr < mmap_min_addr ||
>  		    !slice_area_is_free(mm, addr, len))
> @@ -538,17 +504,12 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  		slice_copy_mask(&good_mask, maskp);
>  	}
>  
> -	slice_print_mask(" good_mask", &good_mask);
> -	if (compat_maskp)
> -		slice_print_mask(" compat_mask", compat_maskp);
> -
>  	/* First check hint if it's valid or if we have MAP_FIXED */
>  	if (addr != 0 || fixed) {
>  		/* Check if we fit in the good mask. If we do, we just return,
>  		 * nothing else to do
>  		 */
>  		if (slice_check_range_fits(mm, &good_mask, addr, len)) {
> -			slice_dbg(" fits good !\n");
>  			newaddr = addr;
>  			goto return_addr;
>  		}
> @@ -558,13 +519,10 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  		 */
>  		newaddr = slice_find_area(mm, len, &good_mask,
>  					  psize, topdown, high_limit);
> -		if (newaddr != -ENOMEM) {
> -			/* Found within the good mask, we don't have to setup,
> -			 * we thus return directly
> -			 */
> -			slice_dbg(" found area at 0x%lx\n", newaddr);
> +
> +		/* Found within good mask, don't have to setup, thus return directly */
> +		if (newaddr != -ENOMEM)
>  			goto return_addr;
> -		}
>  	}
>  	/*
>  	 * We don't fit in the good mask, check what other slices are
> @@ -572,11 +530,9 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  	 */
>  	slice_mask_for_free(mm, &potential_mask, high_limit);
>  	slice_or_mask(&potential_mask, &potential_mask, &good_mask);
> -	slice_print_mask(" potential", &potential_mask);
>  
>  	if (addr != 0 || fixed) {
>  		if (slice_check_range_fits(mm, &potential_mask, addr, len)) {
> -			slice_dbg(" fits potential !\n");
>  			newaddr = addr;
>  			goto convert;
>  		}
> @@ -586,18 +542,14 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  	if (fixed)
>  		return -EBUSY;
>  
> -	slice_dbg(" search...\n");
> -
>  	/* If we had a hint that didn't work out, see if we can fit
>  	 * anywhere in the good area.
>  	 */
>  	if (addr) {
>  		newaddr = slice_find_area(mm, len, &good_mask,
>  					  psize, topdown, high_limit);
> -		if (newaddr != -ENOMEM) {
> -			slice_dbg(" found area at 0x%lx\n", newaddr);
> +		if (newaddr != -ENOMEM)
>  			goto return_addr;
> -		}
>  	}
>  
>  	/* Now let's see if we can find something in the existing slices
> @@ -618,8 +570,6 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>  		return -ENOMEM;
>  
>  	slice_range_to_mask(newaddr, len, &potential_mask);
> -	slice_dbg(" found potential area at 0x%lx\n", newaddr);
> -	slice_print_mask(" mask", &potential_mask);
>  
>   convert:
>  	/*
> @@ -697,8 +647,6 @@ void slice_init_new_context_exec(struct mm_struct *mm)
>  	struct slice_mask *mask;
>  	unsigned int psize = mmu_virtual_psize;
>  
> -	slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm);
> -
>  	/*
>  	 * In the case of exec, use the default limit. In the
>  	 * case of fork it is just inherited from the mm being
> @@ -730,8 +678,6 @@ void slice_setup_new_exec(void)
>  {
>  	struct mm_struct *mm = current->mm;
>  
> -	slice_dbg("slice_setup_new_exec(mm=%p)\n", mm);
> -
>  	if (!is_32bit_task())
>  		return;
>  
> -- 
> 2.13.3