On Mon,  9 Jan 2012 16:51:55 -0600
Seth Jennings [off-list ref] wrote:

This patchset introduces a new memory allocation library named
zsmalloc.  zsmalloc was designed to fulfill the needs
of users where:
 1) Memory is constrained, preventing contiguous page allocations
    larger than order 0 and
 2) Allocations are all/commonly greater than half a page.

In a generic allocator, an allocation set like this would
cause high fragmentation.  The allocations can't span non-
contiguous page boundaries; therefore, the part of the page
unused by each allocation is wasted.

zsmalloc is a slab-based allocator that uses a non-standard
malloc interface, requiring the user to map the allocation
before accessing it. This allows allocations to span two
non-contiguous pages using virtual memory mapping, greatly
reducing fragmentation in the memory pool.

The changelog doesn't really describe why the code was written and
provides no reason for anyone to merge it.

Perhaps the reason was to clean up and generalise the zram xvmalloc
code.  Perhaps the reason was also to then use zsmalloc somewhere else
in the kernel.  But I really don't know.  This is the most important
part of the patch description and you completely omitted it!


Where will this code live after it escapes from drivers/staging/? mm/?

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>