Re: [PATCH, RFC 0/3] Introduce new O_HOT and O_COLD flags

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> > I cc'd linux-mm to see if there might be an interest in this ... or even
> > if it's worth it: I can also see we don't necessarily want userspace to
> > be able to tamper with our idea of what's hot and cold in the page
> > cache, since we get it primarily from the lru lists.
> >
> > James

The notion of hor and cold in the page allocator refers to processor cache
hotness and is used for pages on the per cpu free lists.

F.e. cold pages are used when I/O is soon expected to occur on them
because we want to avoid having to evict cache lines. Cold pages have been
freed a long time ago.

Hot pages are those that have been recently freed (we know that some
cachelines are present therefore) and thus it is likely that acquisition
by another process will allow that process to reuse the cacheline already
present avoiding a trip to memory.

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Reiser Filesystem Development]     [Ceph FS]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite National Park]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]     [Linux Media]

  Powered by Linux