linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Mike Rapoport <rppt@linux.ibm.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Jeremy Cline <jcline@redhat.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] mm, thp: track fallbacks due to failed memcg charges separately
Date: Tue, 18 Feb 2020 11:34:17 +0200	[thread overview]
Message-ID: <20200218093417.GB24430@linux.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.21.2002172139310.152060@chino.kir.corp.google.com>

On Mon, Feb 17, 2020 at 09:41:40PM -0800, David Rientjes wrote:
> The thp_fault_fallback stat in either /proc/vmstat is incremented if 

Nit:                            ^ "either" here looks wrong

> either the hugepage allocation fails through the page allocator or the 
> hugepage charge fails through mem cgroup.
> 
> This patch leaves this field untouched but adds a new field,
> thp_fault_fallback_charge, which is incremented only when the mem cgroup
> charge fails.
> 
> This distinguishes between faults that want to be backed by hugepages but
> fail due to fragmentation (or low memory conditions) and those that fail
> due to mem cgroup limits.  That can be used to determine the impact of 
> fragmentation on the system by excluding faults that failed due to memcg 
> usage.
> 
> Signed-off-by: David Rientjes <rientjes@google.com>
> ---
>  Documentation/admin-guide/mm/transhuge.rst | 5 +++++
>  include/linux/vm_event_item.h              | 1 +
>  mm/huge_memory.c                           | 2 ++
>  mm/vmstat.c                                | 1 +
>  4 files changed, 9 insertions(+)
> 
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -310,6 +310,11 @@ thp_fault_fallback
>  	is incremented if a page fault fails to allocate
>  	a huge page and instead falls back to using small pages.
>  
> +thp_fault_fallback_charge
> +	is incremented if a page fault fails to charge a huge page and
> +	instead falls back to using small pages even through the

						    ^ though

> +	allocation was successful.
> +
>  thp_collapse_alloc_failed
>  	is incremented if khugepaged found a range
>  	of pages that should be collapsed into one huge page but failed
> diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> --- a/include/linux/vm_event_item.h
> +++ b/include/linux/vm_event_item.h
> @@ -73,6 +73,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  		THP_FAULT_ALLOC,
>  		THP_FAULT_FALLBACK,
> +		THP_FAULT_FALLBACK_CHARGE,
>  		THP_COLLAPSE_ALLOC,
>  		THP_COLLAPSE_ALLOC_FAILED,
>  		THP_FILE_ALLOC,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -597,6 +597,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
>  	if (mem_cgroup_try_charge_delay(page, vma->vm_mm, gfp, &memcg, true)) {
>  		put_page(page);
>  		count_vm_event(THP_FAULT_FALLBACK);
> +		count_vm_event(THP_FAULT_FALLBACK_CHARGE);
>  		return VM_FAULT_FALLBACK;
>  	}
>  
> @@ -1406,6 +1407,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
>  			put_page(page);
>  		ret |= VM_FAULT_FALLBACK;
>  		count_vm_event(THP_FAULT_FALLBACK);
> +		count_vm_event(THP_FAULT_FALLBACK_CHARGE);
>  		goto out;
>  	}
>  
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1254,6 +1254,7 @@ const char * const vmstat_text[] = {
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  	"thp_fault_alloc",
>  	"thp_fault_fallback",
> +	"thp_fault_fallback_charge",
>  	"thp_collapse_alloc",
>  	"thp_collapse_alloc_failed",
>  	"thp_file_alloc",

-- 
Sincerely yours,
Mike.



  parent reply	other threads:[~2020-02-18  9:34 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-18  5:41 [patch] mm, thp: track fallbacks due to failed memcg charges separately David Rientjes
2020-02-18  8:26 ` Kirill A. Shutemov
2020-02-19  1:59   ` David Rientjes
2020-02-18  9:34 ` Mike Rapoport [this message]
2020-02-19  2:29 ` [patch 1/2] mm, shmem: add thp fault alloc and fallback stats David Rientjes
2020-02-19  2:29   ` [patch 2/2] mm, thp: track fallbacks due to failed memcg charges separately David Rientjes
2020-02-19  8:23     ` Mike Rapoport
2020-02-19  3:22   ` [patch 1/2] mm, shmem: add thp fault alloc and fallback stats Yang Shi
2020-02-19  3:44     ` David Rientjes
2020-02-19 17:01       ` Yang Shi
2020-02-20 13:12         ` Kirill A. Shutemov
2020-03-06 17:23           ` Yang Shi
2020-03-06 21:27             ` David Rientjes

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=20200218093417.GB24430@linux.ibm.com \
    --to=rppt@linux.ibm.com \
    --cc=akpm@linux-foundation.org \
    --cc=jcline@redhat.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=rientjes@google.com \
    /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).