Messages in this thread Patch in this message |  | | | From | Andy Whitcroft <> | | Subject | [PATCH] synchronous lumpy: improve commentary on writeback wait | | Date | Tue, 07 Aug 2007 16:31:40 +0100 |
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Improve code commentary on the initial writeback wait in synchronous reclaim mode.
Signed-off-by: Andy Whitcroft <apw@shadowen.org> --- mm/vmscan.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index b1e9291..a6e65d0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -479,6 +479,14 @@ static unsigned long shrink_page_list(struct list_head *page_list, (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO)); if (PageWriteback(page)) { + /* + * Synchronous reclaim is performed in two passes, + * first an asynchronous pass over the list to + * start parallel writeback, and a second synchronous + * pass to wait for the IO to complete. Wait here + * for any page for which writeback has already + * started. + */ if (sync_writeback == PAGEOUT_IO_SYNC && may_enter_fs) wait_on_page_writeback(page); else - 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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