Re: PATCH: Enable use of large memory pages

[Trond Norbye]

On Feb 22, 2008, at 6:38 AM, dormando wrote:

Hey,

Some comments:

Minor bracket style... Most of the code is:

function (blah blah) {

vs some of yours is:

function (blah blah)
{

Fixed

Also:

+    if (prealloc) {
+        /* Allocate everything in a big chunk with malloc */
+        mem_base = malloc(mem_limit);
+        if (mem_base != NULL) {
+            mem_current = mem_base;
+            mem_avail = mem_limit;
+        } else {
+            fprintf(stderr, "ABORT: Failed to allocate requested
memory\n");
+            exit(EXIT_FAILURE);
+        }
+    }

... probably shouldn't bomb out internally on failure.

Fixed. It will fall back to "incremental" allocation if it cannot allocate everything in one big chunk.

Hrm. I think the flow might go over better if 'prealloc' is only set to

true if 'enable_large_pages' returns true. (it's void now, but you get
the idea). If you're not trying to set up a largepage environment,
you're more likely to fail a massive malloc() anyway.

Fixed.

Most of the text needs cleaning up, but I can do that.

However, the biggest issue here is that the whole thing is Solaris
specific :)

So unless you're running solaris, this essentially gives you an option
which will most likely just cause memcached to fail on large systems.

I don't actually know how to make this work under linux offhand.



support? The contiguous allocation doesn't give all that much benefit
otherwise.

Something something hugetlb. I can do the sysadmin-y parts and allocate the 2MB pages in the OS, but will have to read up on the programmer- y parts. What do you think about removing the option if built without the proper

Done.

Trond

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