Re: pgsql: Allow to trigger kernel writeback after a configurable number of

Tom,

On 2016-03-11 01:29:09 +0000, Andres Freund wrote:
> Several operating systems allow some control over the kernel page
> cache. Linux has sync_file_range(2), several posix systems have msync(2)
> and posix_fadvise(2). sync_file_range(2) is preferable because it
> requires no special setup, whereas msync() requires the to-be-flushed
> range to be mmap'ed. For the purpose of flushing dirty data
> posix_fadvise(2) is the worst alternative, as flushing dirty data is
> just a side-effect of POSIX_FADV_DONTNEED, which also removes the pages
> from the page cache.  Thus the feature is enabled by default only on
> linux, but can be enabled on all systems that have any of the above
> APIs.

This broke gaur:
http://pgbuildfarm.org/cgi-bin/show_log.pl?nm=gaur&dt=2016-03-12%2005%3A44%3A25

I'm planning to add a #ifndef MAP_FAILED #define MAP_FAILED ((void*)
(-1)).

Unless HPPA simply has that defined elsewhere?

Greetings,

Andres Freund