Re: [PATCH v2] mm: use only per-device readahead limit

2015-08-24 Thread Konstantin Khlebnikov
On 24.08.2015 14:57, Roman Gushchin wrote: Maximal readahead size is limited now by two values: 1) by global 2Mb constant (MAX_READAHEAD in max_sane_readahead()) 2) by configurable per-device value* (bdi->ra_pages) There are devices, which require custom readahead limit. For instance, for RAIDs

[PATCH v2] mm: use only per-device readahead limit

2015-08-24 Thread Roman Gushchin
Maximal readahead size is limited now by two values: 1) by global 2Mb constant (MAX_READAHEAD in max_sane_readahead()) 2) by configurable per-device value* (bdi->ra_pages) There are devices, which require custom readahead limit. For instance, for RAIDs it's calculated as number of devices multipli