Previously POSIX_FADV_DONTNEED would start writeback for the entire file when the bdi was not write congested. This negatively impacts performance if the file contians dirty pages outside of the requested range. This change uses __filemap_fdatawrite_range() to only initiate writeback for the requested range. Signed-off-by: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxxx> --- mm/fadvise.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/fadvise.c b/mm/fadvise.c index 8d723c9..469491e 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -117,7 +117,8 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice) break; case POSIX_FADV_DONTNEED: if (!bdi_write_congested(mapping->backing_dev_info)) - filemap_flush(mapping); + __filemap_fdatawrite_range(mapping, offset, endbyte, + WB_SYNC_NONE); /* First and last FULL page! */ start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT; -- 1.7.6 --------------------------------------------------------------- This email, along with any attachments, is confidential. If you believe you received this message in error, please contact the sender immediately and delete all copies of the message. Thank you. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>