From: David Laight <David.Laight@ACULAB.COM>
To: "'Rahul Lakkireddy'" <rahul.lakkireddy@chelsio.com>,
Thomas Gleixner <tglx@linutronix.de>
Cc: "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: Tue, 20 Mar 2018 14:40:19 +0000 [thread overview]
Message-ID: <5f43882155104f50bbd2e5cf63d432f2@AcuMS.aculab.com> (raw)
In-Reply-To: <20180320133206.GB25574@chelsio.com>
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.
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().)
David
next prev parent reply other threads:[~2018-03-20 14:39 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 [this message]
2018-03-21 12:28 ` Rahul Lakkireddy
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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