linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Gavin Shan <gshan@redhat.com>, linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
	will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com,
	shan.gavin@gmail.com
Subject: Re: [PATCH v3 10/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D modifying tests
Date: Thu, 22 Jul 2021 10:39:08 +0530	[thread overview]
Message-ID: <f636f6ae-ea37-aac6-47cd-ff97ceaa5268@arm.com> (raw)
In-Reply-To: <20210719130613.334901-11-gshan@redhat.com>



On 7/19/21 6:36 PM, Gavin Shan wrote:
> This uses struct pgtable_debug_args in PGD/P4D modifying tests. No
> allocated huge page is used in these tests. Besides, the unused
> variable @saved_p4dp and @saved_pudp are dropped.

Please dont drop  @saved_p4dp and @saved_pudp just yet.

> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
>  mm/debug_vm_pgtable.c | 86 +++++++++++++++++++------------------------
>  1 file changed, 38 insertions(+), 48 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 57b7ead0708b..5ebacc940b68 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -520,27 +520,26 @@ static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
>  #endif /* PAGETABLE_PUD_FOLDED */
>  
>  #ifndef __PAGETABLE_P4D_FOLDED
> -static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
> +static void __init p4d_clear_tests(struct pgtable_debug_args *args)
>  {
> -	p4d_t p4d = READ_ONCE(*p4dp);
> +	p4d_t p4d = READ_ONCE(*(args->p4dp));
>  
> -	if (mm_pud_folded(mm))
> +	if (mm_pud_folded(args->mm))
>  		return;
>  
>  	pr_debug("Validating P4D clear\n");
>  	p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
> -	WRITE_ONCE(*p4dp, p4d);
> -	p4d_clear(p4dp);
> -	p4d = READ_ONCE(*p4dp);
> +	WRITE_ONCE(*(args->p4dp), p4d);
> +	p4d_clear(args->p4dp);
> +	p4d = READ_ONCE(*(args->p4dp));
>  	WARN_ON(!p4d_none(p4d));
>  }
>  
> -static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
> -				      pud_t *pudp)
> +static void __init p4d_populate_tests(struct pgtable_debug_args *args)
>  {
>  	p4d_t p4d;
>  
> -	if (mm_pud_folded(mm))
> +	if (mm_pud_folded(args->mm))
>  		return;
>  
>  	pr_debug("Validating P4D populate\n");
> @@ -548,34 +547,33 @@ static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
>  	 * This entry points to next level page table page.
>  	 * Hence this must not qualify as p4d_bad().
>  	 */
> -	pud_clear(pudp);
> -	p4d_clear(p4dp);
> -	p4d_populate(mm, p4dp, pudp);
> -	p4d = READ_ONCE(*p4dp);
> +	pud_clear(args->pudp);
> +	p4d_clear(args->p4dp);
> +	p4d_populate(args->mm, args->p4dp, args->start_pudp);
> +	p4d = READ_ONCE(*(args->p4dp));
>  	WARN_ON(p4d_bad(p4d));
>  }
>  
> -static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
> +static void __init pgd_clear_tests(struct pgtable_debug_args *args)
>  {
> -	pgd_t pgd = READ_ONCE(*pgdp);
> +	pgd_t pgd = READ_ONCE(*(args->pgdp));
>  
> -	if (mm_p4d_folded(mm))
> +	if (mm_p4d_folded(args->mm))
>  		return;
>  
>  	pr_debug("Validating PGD clear\n");
>  	pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
> -	WRITE_ONCE(*pgdp, pgd);
> -	pgd_clear(pgdp);
> -	pgd = READ_ONCE(*pgdp);
> +	WRITE_ONCE(*(args->pgdp), pgd);
> +	pgd_clear(args->pgdp);
> +	pgd = READ_ONCE(*(args->pgdp));
>  	WARN_ON(!pgd_none(pgd));
>  }
>  
> -static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
> -				      p4d_t *p4dp)
> +static void __init pgd_populate_tests(struct pgtable_debug_args *args)
>  {
>  	pgd_t pgd;
>  
> -	if (mm_p4d_folded(mm))
> +	if (mm_p4d_folded(args->mm))
>  		return;
>  
>  	pr_debug("Validating PGD populate\n");
> @@ -583,23 +581,17 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
>  	 * This entry points to next level page table page.
>  	 * Hence this must not qualify as pgd_bad().
>  	 */
> -	p4d_clear(p4dp);
> -	pgd_clear(pgdp);
> -	pgd_populate(mm, pgdp, p4dp);
> -	pgd = READ_ONCE(*pgdp);
> +	p4d_clear(args->p4dp);
> +	pgd_clear(args->pgdp);
> +	pgd_populate(args->mm, args->pgdp, args->start_p4dp);
> +	pgd = READ_ONCE(*(args->pgdp));
>  	WARN_ON(pgd_bad(pgd));
>  }
>  #else  /* !__PAGETABLE_P4D_FOLDED */
> -static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
> -static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
> -static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
> -				      pud_t *pudp)
> -{
> -}
> -static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
> -				      p4d_t *p4dp)
> -{
> -}
> +static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
> +static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
> +static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
> +static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
>  #endif /* PAGETABLE_P4D_FOLDED */
>  
>  static void __init pte_clear_tests(struct pgtable_debug_args *args)
> @@ -1135,8 +1127,8 @@ static int __init debug_vm_pgtable(void)
>  	struct vm_area_struct *vma;
>  	struct mm_struct *mm;
>  	pgd_t *pgdp;
> -	p4d_t *p4dp, *saved_p4dp;
> -	pud_t *pudp, *saved_pudp;
> +	p4d_t *p4dp;
> +	pud_t *pudp;
>  	pmd_t *pmdp, *saved_pmdp, pmd;
>  	pgtable_t saved_ptep;
>  	unsigned long vaddr;
> @@ -1180,8 +1172,6 @@ static int __init debug_vm_pgtable(void)
>  	 * page table pages.
>  	 */
>  	pmd = READ_ONCE(*pmdp);
> -	saved_p4dp = p4d_offset(pgdp, 0UL);
> -	saved_pudp = pud_offset(p4dp, 0UL);
>  	saved_pmdp = pmd_offset(pudp, 0UL);
>  	saved_ptep = pmd_pgtable(pmd);
>  
> @@ -1259,15 +1249,15 @@ static int __init debug_vm_pgtable(void)
>  	pud_populate_tests(&args);
>  	spin_unlock(ptl);
>  
> -	spin_lock(&mm->page_table_lock);
> -	p4d_clear_tests(mm, p4dp);
> -	pgd_clear_tests(mm, pgdp);
> -	p4d_populate_tests(mm, p4dp, saved_pudp);
> -	pgd_populate_tests(mm, pgdp, saved_p4dp);
> -	spin_unlock(&mm->page_table_lock);
> +	spin_lock(&(args.mm->page_table_lock));
> +	p4d_clear_tests(&args);
> +	pgd_clear_tests(&args);
> +	p4d_populate_tests(&args);
> +	pgd_populate_tests(&args);
> +	spin_unlock(&(args.mm->page_table_lock));
>  
> -	p4d_free(mm, saved_p4dp);
> -	pud_free(mm, saved_pudp);
> +	p4d_free(mm, p4d_offset(pgdp, 0UL));
> +	pud_free(mm, pud_offset(p4dp, 0UL));

Please keep @saved_pudp and @saved_p4dp declaration, assignment and
usage unchanged for now. Drop them only during [PATCH 11/12]. So in
each patch like these, drop the elements only if there is an unused
warning during build.

There are two set of page table debug elements i.e old and new. The
test is transitioning from old to new. Even after the transition is
complete, the old elements are properly declared, initialized and
freed up. Entire old set should be dropped only in [PATCH 11/12].

>  	pmd_free(mm, saved_pmdp);
>  	pte_free(mm, saved_ptep);
>  
>


  reply	other threads:[~2021-07-22  5:08 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-19 13:06 [PATCH v3 00/12] mm/debug_vm_pgtable: Enhancements Gavin Shan
2021-07-19 13:06 ` [PATCH v3 01/12] mm/debug_vm_pgtable: Introduce struct pgtable_debug_args Gavin Shan
2021-07-21  5:44   ` Anshuman Khandual
2021-07-21 10:20     ` Gavin Shan
2021-07-21 10:39       ` Anshuman Khandual
2021-07-21 10:59         ` Anshuman Khandual
2021-07-21 11:59           ` Gavin Shan
2021-07-22  4:41       ` Anshuman Khandual
2021-07-22  6:23         ` Gavin Shan
2021-07-22  7:08           ` Anshuman Khandual
2021-07-23  0:43             ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 02/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in basic tests Gavin Shan
2021-07-21  5:57   ` Anshuman Khandual
2021-07-21 11:57     ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 03/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in leaf and savewrite tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 04/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in protnone and devmap tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 05/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in soft_dirty and swap tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 06/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and thp tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 07/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying tests Gavin Shan
2021-07-22  5:56   ` Anshuman Khandual
2021-07-22  6:37     ` Gavin Shan
2021-07-23  2:39       ` Anshuman Khandual
2021-07-23  4:23         ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 08/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PMD " Gavin Shan
2021-07-22  5:45   ` Anshuman Khandual
2021-07-22  6:41     ` Gavin Shan
2021-07-22  7:11       ` Anshuman Khandual
2021-07-23  1:00         ` Gavin Shan
2021-07-23  2:33           ` Anshuman Khandual
2021-07-19 13:06 ` [PATCH v3 09/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PUD " Gavin Shan
2021-07-22  5:39   ` Anshuman Khandual
2021-07-22  6:47     ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 10/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D " Gavin Shan
2021-07-22  5:09   ` Anshuman Khandual [this message]
2021-07-22  6:50     ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 11/12] mm/debug_vm_pgtable: Remove unused code Gavin Shan
2021-07-22  4:51   ` Anshuman Khandual
2021-07-22  6:53     ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 12/12] mm/debug_vm_pgtable: Fix corrupted page flag Gavin Shan
2021-07-21 10:18   ` Anshuman Khandual
2021-07-21 12:03     ` Gavin Shan
2021-07-22  3:51       ` Anshuman Khandual
2021-07-22  6:54         ` Gavin Shan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f636f6ae-ea37-aac6-47cd-ff97ceaa5268@arm.com \
    --to=anshuman.khandual@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=catalin.marinas@arm.com \
    --cc=chuhu@redhat.com \
    --cc=gshan@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=shan.gavin@gmail.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).