File Block Prefetching

[gullu]

Hi,

File system implemented in LINUX/UNIX has the capability to prefetch
blocks of files from disk that can help a lot in speeding up
sequential speed up. The prefetcher does not always prefetch a block
and in steady state a sequential access can result in a file cache
miss as the prefetcher did not prefetch a block into the file cache.
In steady state after around 15 file blocks there is a file cache
miss.

Is there a construct or API provided in C/C++ that can force the file
system prefetcher to prefetch data from the disk?

Thanks,
gullu

 

[Thorsten Kiefer]

Hi,

File system implemented in LINUX/UNIX has the capability to prefetch
blocks of files from disk that can help a lot in speeding up
sequential speed up. The prefetcher does not always prefetch a block
and in steady state a sequential access can result in a file cache
miss as the prefetcher did not prefetch a block into the file cache.
In steady state after around 15 file blocks there is a file cache
miss.

Is there a construct or API provided in C/C++ that can force the file
system prefetcher to prefetch data from the disk?

Thanks,
gullu

How about this :
for(int i = 0;i < 123442512;++i) {
do_something_with(read(fd));
if(i % 1024 == 0){
seek(fd,i+1024);
read(fd);
seek(i);
}
}

??