From: Rahul Lakkireddy <rahul.lakkireddy@chelsio•com>
To: David Laight <David.Laight@ACULAB•COM>
Cc: Thomas Gleixner <tglx@linutronix•de>,
"x86@kernel•org" <x86@kernel•org>,
"linux-kernel@vger•kernel.org" <linux-kernel@vger•kernel.org>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>,
"mingo@redhat•com" <mingo@redhat•com>,
"hpa@zytor•com" <hpa@zytor•com>,
"davem@davemloft•net" <davem@davemloft•net>,
"akpm@linux-foundation•org" <akpm@linux-foundation•org>,
"torvalds@linux-foundation•org" <torvalds@linux-foundation•org>,
Ganesh GR <ganeshgr@chelsio•com>,
Nirranjan Kirubaharan <nirranjan@chelsio•com>,
Indranil Choudhury <indranil@chelsio•com>
Subject: Re: [RFC PATCH 2/3] x86/io: implement 256-bit IO read and write
Date: Wed, 21 Mar 2018 17:58:08 +0530 [thread overview]
Message-ID: <20180321122807.GB3245@chelsio.com> (raw)
In-Reply-To: <5f43882155104f50bbd2e5cf63d432f2@AcuMS.aculab.com>
On Tuesday, March 03/20/18, 2018 at 20:10:19 +0530, David Laight wrote:
> From: Rahul Lakkireddy
> > Sent: 20 March 2018 13:32
> ...
> > On High Availability Server, the logs of the failing system must be
> > collected as quickly as possible. So, we're concerned with the amount
> > of time taken to collect our large on-chip memory. We see improvement
> > in doing 256-bit reads at a time.
>
> Two other options:
>
> 1) Get the device to DMA into host memory.
>
Unfortunately, our device doesn't support doing DMA of on-chip memory.
> 2) Use mmap() (and vm_iomap_memory() in your driver) to get direct
> userspace access to the (I assume) PCIe memory space.
> You can then use whatever copy instructions the cpu has.
> (Just don't use memcpy().)
>
We also need to collect this in kernel space i.e. from crash recovery
kernel.
Thanks,
Rahul
next prev parent reply other threads:[~2018-03-21 12:28 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-19 14:20 [RFC PATCH 0/3] kernel: add support for 256-bit IO access Rahul Lakkireddy
2018-03-19 14:20 ` [RFC PATCH 1/3] include/linux: add 256-bit IO accessors Rahul Lakkireddy
2018-03-19 14:20 ` [RFC PATCH 2/3] x86/io: implement 256-bit IO read and write Rahul Lakkireddy
2018-03-19 14:43 ` Thomas Gleixner
2018-03-20 13:32 ` Rahul Lakkireddy
2018-03-20 13:44 ` Andy Shevchenko
2018-03-21 12:27 ` Rahul Lakkireddy
2018-03-20 14:40 ` David Laight
2018-03-21 12:28 ` Rahul Lakkireddy [this message]
2018-03-20 14:42 ` Alexander Duyck
2018-03-21 12:28 ` Rahul Lakkireddy
2018-03-22 1:26 ` Linus Torvalds
2018-03-22 10:48 ` David Laight
2018-03-22 17:16 ` Linus Torvalds
2018-03-19 14:20 ` [RFC PATCH 3/3] cxgb4: read on-chip memory 256-bits at a time Rahul Lakkireddy
2018-03-19 14:53 ` [RFC PATCH 0/3] kernel: add support for 256-bit IO access David Laight
2018-03-19 15:05 ` Thomas Gleixner
2018-03-19 15:19 ` David Laight
2018-03-19 15:37 ` Thomas Gleixner
2018-03-19 15:53 ` David Laight
2018-03-19 16:29 ` Linus Torvalds
2018-03-20 8:26 ` Ingo Molnar
2018-03-20 8:38 ` Thomas Gleixner
2018-03-20 9:08 ` Ingo Molnar
2018-03-20 9:41 ` Thomas Gleixner
2018-03-20 9:59 ` David Laight
2018-03-20 10:54 ` Ingo Molnar
2018-03-20 13:30 ` David Laight
2018-04-03 8:49 ` Pavel Machek
2018-04-03 10:36 ` Ingo Molnar
2018-03-20 14:57 ` Andy Lutomirski
2018-03-20 15:10 ` David Laight
2018-03-21 0:39 ` Andy Lutomirski
2018-03-20 18:01 ` Linus Torvalds
2018-03-21 6:32 ` Ingo Molnar
2018-03-21 15:45 ` Andy Lutomirski
2018-03-22 9:36 ` Ingo Molnar
2018-03-21 7:46 ` Ingo Molnar
2018-03-21 18:15 ` Linus Torvalds
2018-03-22 9:33 ` Ingo Molnar
2018-03-22 17:40 ` Alexei Starovoitov
2018-03-22 17:44 ` Andy Lutomirski
2018-03-22 10:35 ` David Laight
2018-03-22 12:48 ` David Laight
2018-03-22 17:07 ` Linus Torvalds
2018-03-19 15:27 ` Christoph Hellwig
2018-03-20 13:45 ` Rahul Lakkireddy
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