> Here's a new version of my shared page tables patch.
>
> The primary purpose of sharing page tables is improved performance for
> large applications that share big memory areas between multiple processes.
> It eliminates the redundant page tables and significantly reduces the
> number of minor page faults. Tests show significant performance
> improvement for large database applications, including those using large
> pages. There is no measurable performance degradation for small processes.
Tried to get this running with CONFIG_PTSHARE and CONFIG_PTSHARE_PTE on
s390x. Unfortunately it crashed on boot, because pt_share_pte
returned a broken pte pointer:
> +pte_t *pt_share_pte(struct vm_area_struct *vma, unsigned long address, pmd_t *pmd,
> + ...
> + pmd_val(spmde) = 0;
> + ...
> + if (pmd_present(spmde)) {
This is wrong. A pmd_val of 0 will make pmd_present return true on s390x
which is not what you want.
Should be pmd_clear(&spmde).
> +pmd_t *pt_share_pmd(struct vm_area_struct *vma, unsigned long address, pud_t *pud,
> + ...
> + pud_val(spude) = 0;
Should be pud_clear, I guess :)
Thanks,
Heiko
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
