Re: [PATCH] X86-32: Allocate 256 bytes for pgd in PAE paging

2014-12-17 Thread Thomas Gleixner
On Tue, 16 Dec 2014, Fenghua Yu wrote: > @@ -1,5 +1,6 @@ > #include > #include > +#include > #include > #include > #include > @@ -276,7 +277,27 @@ pgd_t *pgd_alloc(struct mm_struct *mm) > pgd_t *pgd; > pmd_t *pmds[PREALLOCATED_PMDS]; > > + /* > + * Xen paravirt ass

[PATCH] X86-32: Allocate 256 bytes for pgd in PAE paging

2014-12-16 Thread Fenghua Yu
From: Fenghua Yu X86 32-bit machine and kernel use PAE paging, which currently wastes about 4K of memory per process on Linux where we have to reserve an entire page to support a single 256-byte PGD structure. It would be a very good thing if we could eliminate that wastage. Signed-off-by: Feng