lkml.org 
[lkml]   [2009]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[RFC patch 11/41] ltt-relay: cache pages address
    page_address is not fast in some systems,
    we should cache it.

    Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    ---
    include/linux/ltt-relay.h | 4 ++--
    ltt/ltt-relay-alloc.c | 10 +++++-----
    2 files changed, 7 insertions(+), 7 deletions(-)

    Index: linux-2.6-lttng/include/linux/ltt-relay.h
    ===================================================================
    --- linux-2.6-lttng.orig/include/linux/ltt-relay.h 2009-03-05 16:07:47.000000000 -0500
    +++ linux-2.6-lttng/include/linux/ltt-relay.h 2009-03-05 16:07:47.000000000 -0500
    @@ -34,6 +34,7 @@ struct rchan_buf;

    struct buf_page {
    struct page *page;
    + void *virt; /* page address of the struct page */
    size_t offset; /* page offset in the buffer */
    struct list_head list; /* buffer linked list */
    };
    @@ -286,8 +287,7 @@ static inline int ltt_relay_write(struct

    page = ltt_relay_cache_page(buf, &buf->wpage, page, offset);
    pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
    - ltt_relay_do_copy(page_address(page->page)
    - + (offset & ~PAGE_MASK), src, pagecpy);
    + ltt_relay_do_copy(page->virt + (offset & ~PAGE_MASK), src, pagecpy);

    if (unlikely(len != pagecpy))
    _ltt_relay_write(buf, offset, src, len, page, pagecpy);
    Index: linux-2.6-lttng/ltt/ltt-relay-alloc.c
    ===================================================================
    --- linux-2.6-lttng.orig/ltt/ltt-relay-alloc.c 2009-03-05 16:07:47.000000000 -0500
    +++ linux-2.6-lttng/ltt/ltt-relay-alloc.c 2009-03-05 16:07:47.000000000 -0500
    @@ -54,6 +54,7 @@ static int relay_alloc_buf(struct rchan_
    goto depopulate;
    }
    list_add_tail(&buf_page->list, &buf->pages);
    + buf_page->virt = page_address(buf_page->page);
    buf_page->offset = (size_t)i << PAGE_SHIFT;
    set_page_private(buf_page->page, (unsigned long)buf_page);
    if (i == 0) {
    @@ -529,8 +530,8 @@ void _ltt_relay_write(struct rchan_buf *

    page = ltt_relay_cache_page(buf, &buf->wpage, page, offset);
    pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
    - ltt_relay_do_copy(page_address(page->page)
    - + (offset & ~PAGE_MASK), src, pagecpy);
    + ltt_relay_do_copy(page->virt
    + + (offset & ~PAGE_MASK), src, pagecpy);
    } while (unlikely(len != pagecpy));
    }
    EXPORT_SYMBOL_GPL(_ltt_relay_write);
    @@ -556,8 +557,7 @@ int ltt_relay_read(struct rchan_buf *buf
    for (;;) {
    page = ltt_relay_cache_page(buf, &buf->rpage, page, offset);
    pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
    - memcpy(dest, page_address(page->page) + (offset & ~PAGE_MASK),
    - pagecpy);
    + memcpy(dest, page->virt + (offset & ~PAGE_MASK), pagecpy);
    len -= pagecpy;
    if (likely(!len))
    break;
    @@ -610,7 +610,7 @@ void *ltt_relay_offset_address(struct rc
    if (offset < page->offset || offset >= page->offset + PAGE_SIZE)
    buf->hpage[odd] = page = buf->wpage;
    page = ltt_relay_cache_page(buf, &buf->hpage[odd], page, offset);
    - return page_address(page->page) + (offset & ~PAGE_MASK);
    + return page->virt + (offset & ~PAGE_MASK);
    }
    EXPORT_SYMBOL_GPL(ltt_relay_offset_address);

    --
    Mathieu Desnoyers
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68


    \
     
     \ /
      Last update: 2009-03-06 00:35    [W:0.023 / U:0.596 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site