Messages in this thread | | | Date | Fri, 21 Aug 2015 11:17:43 -0700 | Subject | Re: [PATCH] mm: use only per-device readahead limit | From | Linus Torvalds <> |
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On Fri, Aug 21, 2015 at 10:12 AM, Roman Gushchin <klamm@yandex-team.ru> wrote: > > There are devices, which require custom readahead limit. > For instance, for RAIDs it's calculated as number of devices > multiplied by chunk size times 2.
So afaik, the default read-ahead size is 128kB, which is actually smaller than the old 512-page limit.
Which means that you probably changed "ra_pages" somehow. Is it some system tool that does that automatically, and if so based on what, exactly?
I'm also slightly worried about the fact that now the max read-ahead may actually be zero, and/or basically infinite (there's a ioctl to set it that only tests that it's not negative). Does everything react ok to that?
Linus
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