On 18 June 2013 10:20, Glenn Fowler g...@research.att.com wrote:
you showed ast grep strace output but not gnu grep
gnu /usr/bin/grep does read of varying chunk sizes on my redhat linux
for NFS files the chunk sizes were around 32Ki
I added some test options to the SFIO_OPTIONS env var
On Fri, 13 Sep 2013 17:14:03 +0200 Lionel Cons wrote:
On 18 June 2013 10:20, Glenn Fowler g...@research.att.com wrote:
you showed ast grep strace output but not gnu grep
gnu /usr/bin/grep does read of varying chunk sizes on my redhat linux
for NFS files the chunk sizes were around 32Ki
Glenn, shared mmap() mapping do not have any impact on fork()
performance, at least on VM architectures who can share pages (this is
common practice since at least SystemV, and no modern Unix or Linux
exists which does not do copy-on-write, but more on that below) The
pages are not even touched,
On Fri, 13 Sep 2013 23:14:22 +0200 =?KOI8-R?B?z8zYx8Egy9LZ1sHOz9fTy8HR?= wrote:
Glenn, shared mmap() mapping do not have any impact on fork()
performance, at least on VM architectures who can share pages (this is
common practice since at least SystemV, and no modern Unix or Linux
exists which
No, this is not copy on write, this is
check-what-to-do-on-access-when-not-mapped. The short explanation is,
that the fork() is not the time when an action in the VM system will
happen, its the time of the first access to a page, which is not
mapped yet, in the current process, when an action will
we're getting close
again we're not interested in the pages
but the metadata for the pages
this may be based on incorrect assumptions ...
1Gib mapped and 8Kib page size = 131072 entries for address-to-page lookup
at fork() time the parent process has that 131072 entry table in hand
what does the
Message-
From: ast-users-boun...@lists.research.att.com [mailto:ast-users-
boun...@lists.research.att.com] On Behalf Of Glenn Fowler
Sent: Friday, September 13, 2013 5:00 PM
Subject: Re: [ast-users] Thank you for the grep builtin!
we're getting close
again we're not interested
packet.
Regards,
John Haller
-Original Message-
From: ast-users-boun...@lists.research.att.com [mailto:ast-users-
boun...@lists.research.att.com] On Behalf Of Glenn Fowler
Sent: Friday, September 13, 2013 5:00 PM
Subject: Re: [ast-users] Thank you for the grep builtin!
we're
packet to the end of the next packet.
Regards,
John Haller
-Original Message-
From: ast-users-boun...@lists.research.att.com [mailto:ast-users-
boun...@lists.research.att.com] On Behalf Of Glenn Fowler
Sent: Friday, September 13, 2013 5:00 PM
Subject: Re: [ast-users] Thank
On 18 June 2013 10:20, Glenn Fowler g...@research.att.com wrote:
you showed ast grep strace output but not gnu grep
sorry, I didn't verify the data send by my staff
gnu /usr/bin/grep does read of varying chunk sizes on my redhat linux
for NFS files the chunk sizes were around 32Ki
chunk
great - any soft numbers on improvement?
On Thu, 6 Jun 2013 11:23:27 +0200 Lionel Cons wrote:
I'd like say Thank you for adding the grep builtin to ksh93.
Today we figured out that this gave a major performance boost and
helped a lot working around shoddy or broken grep implementations.
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