Gregory, On 4/9/06 2:04 PM, "Gregory Maxwell" <[EMAIL PROTECTED]> wrote:
> It increases Linux's maximum readahead from 128K to 1meg .. and it > should be smart enough that you could crank it up further without too > much risk of hurting performance elsewhere. Interesting - we are now routinely using the "blockdev --setra" to set the block device readahead and our common setting now is 16MB, so I will look at how the behavior of this adaptive readahead affects normal query workload. >From the patch: Normally, the kernel uses a stock readahead logic that is well understood and well tuned. This option enables a much complex and feature rich one. It is more aggressive and memory efficient in doing readahead, and supports some less-common access patterns such as reading backward and reading sparsely. However, due to the great diversity of real world applications, it might not fit everyone. - Luke ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly