From: Waiman Long <waiman.long@hpe.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Scott J Norton <scott.norton@hp.com>,
Douglas Hatch <doug.hatch@hp.com>
Subject: Re: [PATCH v2 3/3] vfs: Enable list batching for the superblock's inode list
Date: Mon, 01 Feb 2016 17:03:53 -0500 [thread overview]
Message-ID: <56AFD649.9030707@hpe.com> (raw)
In-Reply-To: <20160201174526.GA3696@two.firstfloor.org>
On 02/01/2016 12:45 PM, Andi Kleen wrote:
>> I'm wondering, why are inode_sb_list_add()/del() even called for a presumably
>> reasonably well cached benchmark running on a system with enough RAM? Are these
>> perhaps thousands of temporary files, already deleted, and released when all the
>> file descriptors are closed as part of sys_exit()?
>>
>> If that's the case then I suspect an even bigger win would be not just to batch
>> the (sb-)global list fiddling, but to potentially turn the sb list into a
>> percpu_alloc() managed set of per CPU lists? It's a bigger change, but it could
> We had such a patch in the lock elision patchkit (It avoided a lot
> of cache line bouncing leading to aborts)
>
> https://git.kernel.org/cgit/linux/kernel/git/ak/linux-misc.git/commit/?h=hle315/combined&id=f1cf9e715a40f44086662ae3b29f123cf059cbf4
>
> -Andi
>
>
I like your patch though it cannot be applied cleanly for the current
upstream kernel. I will port it to the current kernel and run my
microbenchmark to see what performance gain I can get.
Cheers,
Longman
next prev parent reply other threads:[~2016-02-01 22:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-29 19:30 [PATCH v2 0/3] lib/list_batch: A simple list insertion/deletion batching facility Waiman Long
2016-01-29 19:30 ` [PATCH v2 1/3] " Waiman Long
2016-02-01 0:47 ` Dave Chinner
2016-02-03 23:11 ` Waiman Long
2016-02-06 23:57 ` Dave Chinner
2016-02-17 1:37 ` Waiman Long
2016-01-29 19:30 ` [PATCH v2 2/3] lib/list_batch, x86: Enable list insertion/deletion batching for x86 Waiman Long
2016-01-29 19:30 ` [PATCH v2 3/3] vfs: Enable list batching for the superblock's inode list Waiman Long
2016-01-30 8:35 ` Ingo Molnar
2016-02-01 17:45 ` Andi Kleen
2016-02-01 22:03 ` Waiman Long [this message]
2016-02-03 22:59 ` Waiman Long
2016-02-06 23:51 ` Dave Chinner
2016-02-01 21:44 ` Waiman Long
2016-02-01 0:04 ` Dave Chinner
2016-02-03 23:01 ` Waiman Long
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