Re: Improve lseek scalability v3

[Josef Bacik]

On Fri, Sep 16, 2011 at 07:00:55AM -0600, Matthew Wilcox wrote:
> On Thu, Sep 15, 2011 at 04:06:46PM -0700, Andi Kleen wrote:
> > Currently generic_file_llseek users synchronize all on the inode i_mutex,
> > which is very heavy handed because it affects even different processes.
> > 
> > This patchkit attempts to make generic_file_llseek (mostly) lockless.
> 
> Yes, but, are there any real workloads which care?  I know will-it-scale
> says that lseek doesn't scale, but any real app which has a seek-heavy
> workload is surely using pread()/pwrite() by now ... after all, they
> were in UNIX98 so they've been a standard for 13 years.
>

Apparently postgresql uses lseek heavily

http://rhaas.blogspot.com/2011/08/linux-and-glibc-scalability.html

Thanks,

Josef 
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