From: Fengguang Wu <fengguang.wu@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-arch@vger.kernel.org
Subject: Re: [PATCH] mm: create a separate slab for page->ptl allocation
Date: Tue, 22 Oct 2013 13:55:12 +0100 [thread overview]
Message-ID: <20131022125512.GA24418@localhost> (raw)
In-Reply-To: <1382442839-7458-1-git-send-email-kirill.shutemov@linux.intel.com>
On Tue, Oct 22, 2013 at 02:53:59PM +0300, Kirill A. Shutemov wrote:
> If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
> is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
> so we loose 24 on each. An average system can easily allocate few tens
> thousands of page->ptl and overhead is significant.
>
> Let's create a separate slab for page->ptl allocation to solve this.
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
In a 4p server, we noticed up to +469.1% increase in will-it-scale page_fault3
test case and +199.8% in vm-scalability case-shm-pread-seq-mt.
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
300409.00 +440.2% 1622770.80 TOTAL will-it-scale.page_fault3.90.threads
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
291257.80 +469.1% 1657582.20 TOTAL will-it-scale.page_fault3.120.threads
...
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
4034831.40 +199.8% 12095649.80 TOTAL vm-scalability.throughput
Thanks,
Fengguang
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WARNING: multiple messages have this Message-ID (diff)
From: Fengguang Wu <fengguang.wu@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-arch@vger.kernel.org
Subject: Re: [PATCH] mm: create a separate slab for page->ptl allocation
Date: Tue, 22 Oct 2013 13:55:12 +0100 [thread overview]
Message-ID: <20131022125512.GA24418@localhost> (raw)
Message-ID: <20131022125512.VhODmczWcOE0Cey3V4Xw6yqwnmbAaUm3ZScYI9u-U7M@z> (raw)
In-Reply-To: <1382442839-7458-1-git-send-email-kirill.shutemov@linux.intel.com>
On Tue, Oct 22, 2013 at 02:53:59PM +0300, Kirill A. Shutemov wrote:
> If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
> is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
> so we loose 24 on each. An average system can easily allocate few tens
> thousands of page->ptl and overhead is significant.
>
> Let's create a separate slab for page->ptl allocation to solve this.
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
In a 4p server, we noticed up to +469.1% increase in will-it-scale page_fault3
test case and +199.8% in vm-scalability case-shm-pread-seq-mt.
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
300409.00 +440.2% 1622770.80 TOTAL will-it-scale.page_fault3.90.threads
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
291257.80 +469.1% 1657582.20 TOTAL will-it-scale.page_fault3.120.threads
...
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
4034831.40 +199.8% 12095649.80 TOTAL vm-scalability.throughput
Thanks,
Fengguang
next prev parent reply other threads:[~2013-10-22 12:55 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-22 11:53 [PATCH] mm: create a separate slab for page->ptl allocation Kirill A. Shutemov
2013-10-22 11:53 ` Kirill A. Shutemov
2013-10-22 12:55 ` Fengguang Wu [this message]
2013-10-22 12:55 ` Fengguang Wu
2013-11-04 10:42 ` Kirill A. Shutemov
2013-11-04 10:42 ` Kirill A. Shutemov
2013-11-05 23:01 ` Andrew Morton
2013-11-05 23:01 ` Andrew Morton
2013-11-05 22:42 ` Kirill A. Shutemov
2013-11-05 22:42 ` Kirill A. Shutemov
2013-11-05 23:56 ` Andrew Morton
2013-11-05 23:56 ` Andrew Morton
2013-11-05 23:13 ` Kirill A. Shutemov
2013-11-05 23:13 ` Kirill A. Shutemov
2013-11-06 0:43 ` Andrew Morton
2013-11-06 0:43 ` Andrew Morton
2013-11-06 9:31 ` Peter Zijlstra
2013-11-06 9:31 ` Peter Zijlstra
2013-11-06 11:18 ` Peter Zijlstra
2013-11-06 11:18 ` Peter Zijlstra
2013-11-06 13:31 ` lockref: Use bloated_spinlocks to avoid explicit config dependencies Kirill A. Shutemov
2013-11-06 13:31 ` Kirill A. Shutemov
2013-11-06 14:32 ` Peter Zijlstra
2013-11-06 14:32 ` Peter Zijlstra
2013-11-06 13:21 ` [PATCH] mm: create a separate slab for page->ptl allocation Kirill A. Shutemov
2013-11-06 13:21 ` Kirill A. Shutemov
2013-11-06 14:30 ` Peter Zijlstra
2013-11-06 14:30 ` Peter Zijlstra
2013-11-06 10:34 ` Will Deacon
2013-11-06 10:34 ` Will Deacon
2013-11-06 10:49 ` Geert Uytterhoeven
2013-11-06 10:49 ` Geert Uytterhoeven
2013-11-06 11:02 ` Peter Zijlstra
2013-11-06 11:02 ` Peter Zijlstra
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