On Thu, Apr 26, 2018 at 8:33 AM, Andres Freund wrote:
> On 2018-04-25 14:41:44 -0400, Robert Haas wrote:
>> On Mon, Apr 16, 2018 at 2:13 AM, Andrew Gierth
>> wrote:
>> > The code that detects sequential behavior can not distinguish between
>> > pread() and lseek+read, it looks only at the actual
On 2018-04-25 14:41:44 -0400, Robert Haas wrote:
> On Mon, Apr 16, 2018 at 2:13 AM, Andrew Gierth
> wrote:
> > The code that detects sequential behavior can not distinguish between
> > pread() and lseek+read, it looks only at the actual offset of the
> > current request compared to the previous on
On Mon, Apr 16, 2018 at 2:13 AM, Andrew Gierth
wrote:
> The code that detects sequential behavior can not distinguish between
> pread() and lseek+read, it looks only at the actual offset of the
> current request compared to the previous one for the same fp.
>
> Thomas> +1 for adopting pread()/pwr
> "Thomas" == Thomas Munro writes:
Thomas> * it's also been claimed that readahead heuristics are not
Thomas> defeated on Linux or FreeBSD, which isn't too surprising
Thomas> because you'd expect it to be about blocks being faulted in,
Thomas> not syscalls
I don't know about linux, but o
On Fri, Jun 23, 2017 at 4:50 AM, Andres Freund wrote:
> On 2017-06-22 12:43:16 -0400, Robert Haas wrote:
>> On Wed, Jan 25, 2017 at 2:52 PM, Andres Freund wrote:
>> > You'll, depending on your workload, still have a lot of lseeks even if
>> > we were to use pread/pwrite because we do lseek(SEEK_E
