Messages in this thread Patch in this message | | | Date | Sun, 25 Sep 2005 16:48:19 +0100 (BST) | From | Hugh Dickins <> | Subject | [PATCH 02/21] mm: copy_pte_range progress fix |
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[PATCH 02/21] mm: copy_pte_range progress fix
My latency breaking in copy_pte_range didn't work as intended: instead of checking at regularish intervals, after the first interval it checked every time around the loop, too impatient to be preempted. Fix that.
Signed-off-by: Hugh Dickins <hugh@veritas.com> ---
mm/memory.c | 14 ++++++++------ 1 files changed, 8 insertions(+), 6 deletions(-)
--- mm01/mm/memory.c 2005-09-21 12:16:59.000000000 +0100 +++ mm02/mm/memory.c 2005-09-24 19:26:38.000000000 +0100 @@ -410,7 +410,7 @@ static int copy_pte_range(struct mm_stru { pte_t *src_pte, *dst_pte; unsigned long vm_flags = vma->vm_flags; - int progress; + int progress = 0; again: dst_pte = pte_alloc_map(dst_mm, dst_pmd, addr); @@ -418,17 +418,19 @@ again: return -ENOMEM; src_pte = pte_offset_map_nested(src_pmd, addr); - progress = 0; spin_lock(&src_mm->page_table_lock); do { /* * We are holding two locks at this point - either of them * could generate latencies in another task on another CPU. */ - if (progress >= 32 && (need_resched() || - need_lockbreak(&src_mm->page_table_lock) || - need_lockbreak(&dst_mm->page_table_lock))) - break; + if (progress >= 32) { + progress = 0; + if (need_resched() || + need_lockbreak(&src_mm->page_table_lock) || + need_lockbreak(&dst_mm->page_table_lock)) + break; + } if (pte_none(*src_pte)) { progress++; continue; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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