mariadb/storage/innodb_plugin/include/buf0lru.h
Satya B abfdf76bbf Applying InnoDB Plugin 1.0.5 snapshot, part 4
From revision r5703 to r5716

Detailed revision comments:

r5703 | marko | 2009-08-27 02:25:00 -0500 (Thu, 27 Aug 2009) | 41 lines
branches/zip: Replace the constant 3/8 ratio that controls the LRU_old
size with the settable global variable innodb_old_blocks_pct. The
minimum and maximum values are 5 and 95 per cent, respectively. The
default is 100*3/8, in line with the old behavior.

ut_time_ms(): New utility function, to return the current time in
milliseconds. TODO: Is there a more efficient timestamp function, such
as rdtsc divided by a power of two?

buf_LRU_old_threshold_ms: New variable, corresponding to
innodb_old_blocks_time. The value 0 is the default behaviour: no
timeout before making blocks 'new'.

bpage->accessed, bpage->LRU_position, buf_pool->ulint_clock: Remove.

bpage->access_time: New field, replacing bpage->accessed. Protected by
buf_pool_mutex instead of bpage->mutex. Updated when a page is created
or accessed the first time in the buffer pool.

buf_LRU_old_ratio, innobase_old_blocks_pct: New variables,
corresponding to innodb_old_blocks_pct

buf_LRU_old_ratio_update(), innobase_old_blocks_pct_update(): Update
functions for buf_LRU_old_ratio, innobase_old_blocks_pct.

buf_page_peek_if_too_old(): Compare ut_time_ms() to bpage->access_time
if buf_LRU_old_threshold_ms && bpage->old.  Else observe
buf_LRU_old_ratio and bpage->freed_page_clock.

buf_pool_t: Add n_pages_made_young, n_pages_not_made_young,
n_pages_made_young_old, n_pages_not_made_young, for statistics.

buf_print(): Display buf_pool->n_pages_made_young,
buf_pool->n_pages_not_made_young.  This function is only for crash
diagnostics.

buf_print_io(): Display buf_pool->LRU_old_len and quantities derived
from buf_pool->n_pages_made_young, buf_pool->n_pages_not_made_young.
This function is invoked by SHOW ENGINE INNODB STATUS.

rb://129 approved by Heikki Tuuri.  This addresses Bug #45015.
r5704 | marko | 2009-08-27 03:31:17 -0500 (Thu, 27 Aug 2009) | 32 lines
branches/zip: Fix a critical bug in fast index creation that could
corrupt the created indexes.

row_merge(): Make "half" an in/out parameter. Determine the offset of
half the output file. Copy the last blocks record-by-record instead of
block-by-block, so that the records can be counted. Check that the
input and output have matching n_rec.

row_merge_sort(): Do not assume that two blocks of size N are merged
into a block of size 2*N. The output block can be shorter than the
input if the last page of each input block is almost empty. Use an
accurate termination condition, based on the "half" computed by
row_merge().

row_merge_read(), row_merge_write(), row_merge_blocks(): Add debug output.

merge_file_t, row_merge_file_create(): Add n_rec, the number of records
in the merge file.

row_merge_read_clustered_index(): Update n_rec.

row_merge_blocks(): Update and check n_rec.

row_merge_blocks_copy(): New function, for copying the last blocks in
row_merge().  Update and check n_rec.

This bug was discovered with a user-supplied test case that creates an
index where the initial temporary file is 249 one-megabyte blocks and
the merged files become smaller. In the test, possible merge record
sizes are 10, 18, and 26 bytes.

rb://150 approved by Sunny Bains.  This addresses Issue #320.
r5705 | marko | 2009-08-27 06:56:24 -0500 (Thu, 27 Aug 2009) | 11 lines
branches/zip: dict_index_find_cols(): On column name lookup failure,
return DB_CORRUPTION (HA_ERR_CRASHED) instead of abnormally
terminating the server.  Also, disable the previously added diagnostic
output to the error log, because mysql-test-run does not like extra
output in the error log.  (Bug #44571)

dict_index_add_to_cache(): Handle errors from dict_index_find_cols().

mysql-test/innodb_bug44571.test: A test case for triggering the bug.

rb://135 approved by Sunny Bains.
r5706 | inaam | 2009-08-27 11:00:27 -0500 (Thu, 27 Aug 2009) | 20 lines
branches/zip rb://147

Done away with following two status variables:

innodb_buffer_pool_read_ahead_rnd
innodb_buffer_pool_read_ahead_seq

Introduced two new status variables:
innodb_buffer_pool_read_ahead = number of pages read as part of
readahead since server startup
innodb_buffer_pool_read_ahead_evicted = number of pages that are read
in as readahead but were evicted before ever being accessed since
server startup i.e.: a measure of how badly our readahead is
performing

SHOW INNODB STATUS will show two extra numbers in buffer pool section:
pages read ahead/sec and pages evicted without access/sec

Approved by: Marko

r5707 | inaam | 2009-08-27 11:20:35 -0500 (Thu, 27 Aug 2009) | 6 lines
branches/zip

Remove unused macros as we erased the random readahead code in r5703.
Also fixed some comments.


r5708 | inaam | 2009-08-27 17:43:32 -0500 (Thu, 27 Aug 2009) | 4 lines
branches/zip

Remove redundant TRUE : FALSE from the return statement

r5709 | inaam | 2009-08-28 01:22:46 -0500 (Fri, 28 Aug 2009) | 5 lines
branches/zip rb://152

Disable display of deprecated parameter innodb_file_io_threads in
'show variables'.

r5714 | marko | 2009-08-31 01:10:10 -0500 (Mon, 31 Aug 2009) | 5 lines
branches/zip: buf_chunk_not_freed(): Do not acquire block->mutex unless
block->page.state == BUF_BLOCK_FILE_PAGE.  Check that block->page.state
makes sense.

Approved by Sunny Bains over the IM.
r5716 | vasil | 2009-08-31 02:47:49 -0500 (Mon, 31 Aug 2009) | 9 lines
branches/zip:

Fix Bug#46718 InnoDB plugin incompatible with gcc 4.1 (at least: on PPC): "Undefined symbol"

by implementing our own check in plug.in instead of using the result from
the check from MySQL because it is insufficient.

Approved by:	Marko (rb://154)
2009-10-08 16:58:37 +05:30

295 lines
11 KiB
C

/*****************************************************************************
Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************/
/**************************************************//**
@file include/buf0lru.h
The database buffer pool LRU replacement algorithm
Created 11/5/1995 Heikki Tuuri
*******************************************************/
#ifndef buf0lru_h
#define buf0lru_h
#include "univ.i"
#include "ut0byte.h"
#include "buf0types.h"
/** The return type of buf_LRU_free_block() */
enum buf_lru_free_block_status {
/** freed */
BUF_LRU_FREED = 0,
/** not freed because the caller asked to remove the
uncompressed frame but the control block cannot be
relocated */
BUF_LRU_CANNOT_RELOCATE,
/** not freed because of some other reason */
BUF_LRU_NOT_FREED
};
/******************************************************************//**
Tries to remove LRU flushed blocks from the end of the LRU list and put them
to the free list. This is beneficial for the efficiency of the insert buffer
operation, as flushed pages from non-unique non-clustered indexes are here
taken out of the buffer pool, and their inserts redirected to the insert
buffer. Otherwise, the flushed blocks could get modified again before read
operations need new buffer blocks, and the i/o work done in flushing would be
wasted. */
UNIV_INTERN
void
buf_LRU_try_free_flushed_blocks(void);
/*==================================*/
/******************************************************************//**
Returns TRUE if less than 25 % of the buffer pool is available. This can be
used in heuristics to prevent huge transactions eating up the whole buffer
pool for their locks.
@return TRUE if less than 25 % of buffer pool left */
UNIV_INTERN
ibool
buf_LRU_buf_pool_running_out(void);
/*==============================*/
/*#######################################################################
These are low-level functions
#########################################################################*/
/** Minimum LRU list length for which the LRU_old pointer is defined */
#define BUF_LRU_OLD_MIN_LEN 512 /* 8 megabytes of 16k pages */
/** Maximum LRU list search length in buf_flush_LRU_recommendation() */
#define BUF_LRU_FREE_SEARCH_LEN (5 + 2 * BUF_READ_AHEAD_AREA)
/******************************************************************//**
Invalidates all pages belonging to a given tablespace when we are deleting
the data file(s) of that tablespace. A PROBLEM: if readahead is being started,
what guarantees that it will not try to read in pages after this operation has
completed? */
UNIV_INTERN
void
buf_LRU_invalidate_tablespace(
/*==========================*/
ulint id); /*!< in: space id */
/********************************************************************//**
Insert a compressed block into buf_pool->zip_clean in the LRU order. */
UNIV_INTERN
void
buf_LRU_insert_zip_clean(
/*=====================*/
buf_page_t* bpage); /*!< in: pointer to the block in question */
/******************************************************************//**
Try to free a block. If bpage is a descriptor of a compressed-only
page, the descriptor object will be freed as well.
NOTE: If this function returns BUF_LRU_FREED, it will not temporarily
release buf_pool_mutex. Furthermore, the page frame will no longer be
accessible via bpage.
The caller must hold buf_pool_mutex and buf_page_get_mutex(bpage) and
release these two mutexes after the call. No other
buf_page_get_mutex() may be held when calling this function.
@return BUF_LRU_FREED if freed, BUF_LRU_CANNOT_RELOCATE or
BUF_LRU_NOT_FREED otherwise. */
UNIV_INTERN
enum buf_lru_free_block_status
buf_LRU_free_block(
/*===============*/
buf_page_t* bpage, /*!< in: block to be freed */
ibool zip, /*!< in: TRUE if should remove also the
compressed page of an uncompressed page */
ibool* buf_pool_mutex_released);
/*!< in: pointer to a variable that will
be assigned TRUE if buf_pool_mutex
was temporarily released, or NULL */
/******************************************************************//**
Try to free a replaceable block.
@return TRUE if found and freed */
UNIV_INTERN
ibool
buf_LRU_search_and_free_block(
/*==========================*/
ulint n_iterations); /*!< in: how many times this has been called
repeatedly without result: a high value means
that we should search farther; if
n_iterations < 10, then we search
n_iterations / 10 * buf_pool->curr_size
pages from the end of the LRU list; if
n_iterations < 5, then we will also search
n_iterations / 5 of the unzip_LRU list. */
/******************************************************************//**
Returns a free block from the buf_pool. The block is taken off the
free list. If it is empty, returns NULL.
@return a free control block, or NULL if the buf_block->free list is empty */
UNIV_INTERN
buf_block_t*
buf_LRU_get_free_only(void);
/*=======================*/
/******************************************************************//**
Returns a free block from the buf_pool. The block is taken off the
free list. If it is empty, blocks are moved from the end of the
LRU list to the free list.
@return the free control block, in state BUF_BLOCK_READY_FOR_USE */
UNIV_INTERN
buf_block_t*
buf_LRU_get_free_block(
/*===================*/
ulint zip_size); /*!< in: compressed page size in bytes,
or 0 if uncompressed tablespace */
/******************************************************************//**
Puts a block back to the free list. */
UNIV_INTERN
void
buf_LRU_block_free_non_file_page(
/*=============================*/
buf_block_t* block); /*!< in: block, must not contain a file page */
/******************************************************************//**
Adds a block to the LRU list. */
UNIV_INTERN
void
buf_LRU_add_block(
/*==============*/
buf_page_t* bpage, /*!< in: control block */
ibool old); /*!< in: TRUE if should be put to the old
blocks in the LRU list, else put to the
start; if the LRU list is very short, added to
the start regardless of this parameter */
/******************************************************************//**
Adds a block to the LRU list of decompressed zip pages. */
UNIV_INTERN
void
buf_unzip_LRU_add_block(
/*====================*/
buf_block_t* block, /*!< in: control block */
ibool old); /*!< in: TRUE if should be put to the end
of the list, else put to the start */
/******************************************************************//**
Moves a block to the start of the LRU list. */
UNIV_INTERN
void
buf_LRU_make_block_young(
/*=====================*/
buf_page_t* bpage); /*!< in: control block */
/******************************************************************//**
Moves a block to the end of the LRU list. */
UNIV_INTERN
void
buf_LRU_make_block_old(
/*===================*/
buf_page_t* bpage); /*!< in: control block */
/**********************************************************************//**
Updates buf_LRU_old_ratio.
@return updated old_pct */
UNIV_INTERN
uint
buf_LRU_old_ratio_update(
/*=====================*/
uint old_pct,/*!< in: Reserve this percentage of
the buffer pool for "old" blocks. */
ibool adjust);/*!< in: TRUE=adjust the LRU list;
FALSE=just assign buf_LRU_old_ratio
during the initialization of InnoDB */
/********************************************************************//**
Update the historical stats that we are collecting for LRU eviction
policy at the end of each interval. */
UNIV_INTERN
void
buf_LRU_stat_update(void);
/*=====================*/
#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/**********************************************************************//**
Validates the LRU list.
@return TRUE */
UNIV_INTERN
ibool
buf_LRU_validate(void);
/*==================*/
#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
#if defined UNIV_DEBUG_PRINT || defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/**********************************************************************//**
Prints the LRU list. */
UNIV_INTERN
void
buf_LRU_print(void);
/*===============*/
#endif /* UNIV_DEBUG_PRINT || UNIV_DEBUG || UNIV_BUF_DEBUG */
/** @name Heuristics for detecting index scan @{ */
/** Reserve this much/BUF_LRU_OLD_RATIO_DIV of the buffer pool for
"old" blocks. Protected by buf_pool_mutex. */
extern uint buf_LRU_old_ratio;
/** The denominator of buf_LRU_old_ratio. */
#define BUF_LRU_OLD_RATIO_DIV 1024
/** Maximum value of buf_LRU_old_ratio.
@see buf_LRU_old_adjust_len
@see buf_LRU_old_ratio_update */
#define BUF_LRU_OLD_RATIO_MAX BUF_LRU_OLD_RATIO_DIV
/** Minimum value of buf_LRU_old_ratio.
@see buf_LRU_old_adjust_len
@see buf_LRU_old_ratio_update
The minimum must exceed
(BUF_LRU_OLD_TOLERANCE + 5) * BUF_LRU_OLD_RATIO_DIV / BUF_LRU_OLD_MIN_LEN. */
#define BUF_LRU_OLD_RATIO_MIN 51
#if BUF_LRU_OLD_RATIO_MIN >= BUF_LRU_OLD_RATIO_MAX
# error "BUF_LRU_OLD_RATIO_MIN >= BUF_LRU_OLD_RATIO_MAX"
#endif
#if BUF_LRU_OLD_RATIO_MAX > BUF_LRU_OLD_RATIO_DIV
# error "BUF_LRU_OLD_RATIO_MAX > BUF_LRU_OLD_RATIO_DIV"
#endif
/** Move blocks to "new" LRU list only if the first access was at
least this many milliseconds ago. Not protected by any mutex or latch. */
extern uint buf_LRU_old_threshold_ms;
/* @} */
/** @brief Statistics for selecting the LRU list for eviction.
These statistics are not 'of' LRU but 'for' LRU. We keep count of I/O
and page_zip_decompress() operations. Based on the statistics we decide
if we want to evict from buf_pool->unzip_LRU or buf_pool->LRU. */
struct buf_LRU_stat_struct
{
ulint io; /**< Counter of buffer pool I/O operations. */
ulint unzip; /**< Counter of page_zip_decompress operations. */
};
/** Statistics for selecting the LRU list for eviction. */
typedef struct buf_LRU_stat_struct buf_LRU_stat_t;
/** Current operation counters. Not protected by any mutex.
Cleared by buf_LRU_stat_update(). */
extern buf_LRU_stat_t buf_LRU_stat_cur;
/** Running sum of past values of buf_LRU_stat_cur.
Updated by buf_LRU_stat_update(). Protected by buf_pool_mutex. */
extern buf_LRU_stat_t buf_LRU_stat_sum;
/********************************************************************//**
Increments the I/O counter in buf_LRU_stat_cur. */
#define buf_LRU_stat_inc_io() buf_LRU_stat_cur.io++
/********************************************************************//**
Increments the page_zip_decompress() counter in buf_LRU_stat_cur. */
#define buf_LRU_stat_inc_unzip() buf_LRU_stat_cur.unzip++
#ifndef UNIV_NONINL
#include "buf0lru.ic"
#endif
#endif