Messages in this thread Patch in this message | | | Date | Thu, 26 Sep 2002 14:55:32 +0100 | From | Stephen Tweedie <> | Subject | [Patch 3/7] 2.4.20-pre4/ext3: evict truncated buffers more easily. |
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Performance tweak: when we truncate a file but encounter pages which are still being journaled from a previous transaction, we can't evict the page from memory immediately.
This patch just makes it a little easier for the VM to evict the page later on: the page is marked unreferenced while we're committing the transaction which pins it, and the commit logic tries to free the page completely once the transaction has committed.
--- linux-2.4-ext3merge/fs/jbd/commit.c.=K0002=.orig Thu Sep 26 12:19:14 2002 +++ linux-2.4-ext3merge/fs/jbd/commit.c Thu Sep 26 12:25:37 2002 @@ -683,13 +683,25 @@ JBUFFER_TRACE(jh, "refile for checkpoint writeback"); __journal_refile_buffer(jh); } else { + struct page *page = bh->b_page; + J_ASSERT_BH(bh, !buffer_dirty(bh)); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); __journal_unfile_buffer(jh); jh->b_transaction = 0; __journal_remove_journal_head(bh); - __brelse(bh); + + if (TryLockPage(page)) { + __brelse(bh); + } else { + __brelse(bh); + page_cache_get(page); + try_to_free_buffers(page, 0); + unlock_page(page); + page_cache_release(page); + } } + spin_unlock(&journal_datalist_lock); } --- linux-2.4-ext3merge/fs/jbd/transaction.c.=K0002=.orig Thu Sep 26 12:19:14 2002 +++ linux-2.4-ext3merge/fs/jbd/transaction.c Thu Sep 26 12:25:37 2002 @@ -1903,8 +1903,17 @@ unlock_journal(journal); if (!offset) { - if (!may_free || !try_to_free_buffers(page, 0)) + if (!may_free || !try_to_free_buffers(page, 0)) { + if (!offset) { + /* We are still using the page, but only + because a transaction is pinning the + page. Once it commits, we want to + encourage the page to be reaped as + quickly as possible. */ + ClearPageReferenced(page); + } return 0; + } J_ASSERT(page->buffers == NULL); } return 1; - 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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