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* 2.5.50-mm2
@ 2002-12-09  8:26 Andrew Morton
  2002-12-13 22:55 ` 2.5.50-mm2 Christoph Hellwig
       [not found] ` <200212092059.06287.tomlins@cam.org>
  0 siblings, 2 replies; 22+ messages in thread
From: Andrew Morton @ 2002-12-09  8:26 UTC (permalink / raw)
  To: lkml, linux-mm


url: http://www.zip.com.au/~akpm/linux/patches/2.5/2.5.50/2.5.50-mm2/

  -> 2.5.50-mm2.gz        Full patch
  -> 2.5.50-mm2-shpte.gz  Up to `shpte-always-on', for Dave to work against

Lots of fixes. Some things dropped for various reasons.  A decent
amount of rework against the high-level writeback code.


Since 2.5.50-mm1:

-fbcon-timer-fix.patch
-hugepage-fixes.patch
-ext3-oldalloc.patch
-simplified-vm-throttling.patch
-page-reclaim-motion.patch
-handle-fail-writepage.patch
-activate-unreleaseable-pages.patch
-ipc_barriers.patch
-signal-speedup.patch
-pf_memdie.patch
-suppress-write-error-warnings.patch
-truncate-speedup.patch
-spill-lru-lists.patch
-readdir-speedup.patch       (Linus fixed all the bugs in it)

 Merged

-epoll-bits-0.57.patch
+epoll.patch

 Davide's latest

-aio-dio-really-submit.patch
-aio-dio-deferred-dirtying.patch
-dio-counting.patch

 Folded into other patches.

-reiserfs-readpages.patch

 Dropped - it was causing fsx-linux failures.

+cputimes_stat.patch

 Put the per-cpu times back into /proc/pid/stat, CONFIGurably

-poll-1-wqalloc.patch
-poll-2-selectalloc.patch
-poll-3-alloc.patch
-poll-4-fast-select.patch
-poll-5-fast-poll.patch
-poll-6-merge.patch

 Dropped.  Increased stack utilisation was a concern, and the performance
 benefits are patchy.  Manfred is taking another look at it.

+deadsched-fix.patch

 Deadline scheduler fix

+shpte-nonlinear.patch

 Fix shared pagetables for nonlinear mappings

+pmd-allocation-fix.patch

 Always allocate PMD's out to the top of the virtual address space.

-dcache_rcu-2-2.5.48.patch
-dcache_rcu-3-2.5.48.patch

 Dropped.  Other changes broke it, and Dipankar is redoing a few things
 anyway.

+filldir-checks.patch

 Some copy_*_user checks.

+vmstats-fixes.patch

 Small vm stats fix and enhancement.

+hugetlb-fixes.patch

 Fixes from Rohit.

+writeback-interaction-fix.patch

 I had a few oddities and bogons in the fs/fs-writeback.c code.  This
 patch is a fair-sized revamp, cleanup and general sort-things-out in
 there.  It works better.

+scalable-zone-protection.patch

 Allow runtime tuning of the lower-zone protection ratio.  Needs work.

+page-wait-table-min-size.patch

 Don't allow a one-slot hashed wait table for wait_on_page()

+ext3-transaction-reserved-blocks.patch

 Fix an ext3 assertion failure which is triggerable with corrupt disk
 contents.

+remove-PF_SYNC.patch

 remove the current->flags:PF_SYNC abomination.  Adds a `sync' arg to
 all writepage implementations to tell them whether they are being
 called for memory cleansing or for data integrity.

+dont-inherit-mlockall.patch

 Don't inherit mlockall(MCL_FUTURE) across forks

+bootmem-alloc-alignment.patch

 Improved coalescing of bootmem regions

+ext23_free_blocks-check.patch

 Additional sanity checks in the block allocator.

+blkdev-rlimit.patch

 Don't apply rlimits to blockdev writes.

+readahead-pinned-memory.patch

 Don't allow gargantuan amounts of memory to be pinned in readahead

-page-walk-api-improvements.patch
-page-walk-api-bugfix.patch

 Folded into page-walk-api.patch

+page-walk-api-update.patch

 New stuff from Ingo (needs splitting up and changelogging...)




All 55 patches:


linus.patch
  cset-1.797.133.2-to-1.857.txt.gz

epoll.patch
  epoll bits 0.59 ...

kgdb.patch

dio-return-partial-result.patch

aio-direct-io-infrastructure.patch
  AIO support for raw/O_DIRECT

deferred-bio-dirtying.patch
  bio dirtying infrastructure

aio-direct-io.patch
  AIO support for raw/O_DIRECT

aio-dio-debug.patch

dio-reduce-context-switch-rate.patch
  Reduced wakeup rate in direct-io code

cputimes_stat.patch
  Retore per-cpu time accounting, with a config option

deprecate-bdflush.patch
  deprecate use of bdflush()

reduce-random-context-switch-rate.patch
  Reduce context switch rate due to the random driver

bcrl-printk.patch

read_zero-speedup.patch
  speed up read_zero() for !CONFIG_MMU

nommu-rmap-locking.patch
  Fix rmap locking for CONFIG_SWAP=n

semtimedop.patch
  semtimedop - semop() with a timeout

writeback-handle-memory-backed.patch
  skip memory-backed filesystems in writeback

remove-fail_writepage.patch
  Remove fail_writepage()

page-reservation.patch
  Page reservation API

wli-show_free_areas.patch
  show_free_areas extensions

inlines-net.patch

rbtree-iosched.patch
  rbtree-based IO scheduler

deadsched-fix.patch
  deadline scheduler fix

quota-smp-locks.patch
  Subject: [PATCH] Quota SMP locks

shpte-ng.patch
  pagetable sharing for ia32

shpte-nonlinear.patch
  shpte: support nonlinear mappings and clean up clear_share_range()

shpte-always-on.patch
  Force CONFIG_SHAREPTE=y for ia32

pmd-allocation-fix.patch
  make sure all PMDs are allocated under PAE mode

ptrace-flush.patch
  Subject: [PATCH] ptrace on 2.5.44

buffer-debug.patch
  buffer.c debugging

warn-null-wakeup.patch

pentium-II.patch
  Pentium-II support bits

radix-tree-overflow-fix.patch
  handle overflows in radix_tree_gang_lookup()

rcu-stats.patch
  RCU statistics reporting

auto-unplug.patch
  self-unplugging request queues

less-unplugging.patch
  Remove most of the blk_run_queues() calls

sync_fs.patch
  Add a sync_fs super_block operation

ext3_sync_fs.patch
  implement ext3_sync_fs

ext3-fsync-speedup.patch
  Clean up ext3_sync_file()

filldir-checks.patch
  copy_user checks in filldir()

vmstats-fixes.patch
  vm accounting fixes and addition

hugetlb-fixes.patch
  hugetlb fixes

writeback-interaction-fix.patch
  fs-writeback rework.

scalable-zone-protection.patch
  Add /proc/sys/vm/lower_zone_protection

page-wait-table-min-size.patch
  Set a minimum hash table size for wait_on_page()

ext3-transaction-reserved-blocks.patch
  Reserve an additional transaction block in ext3_dirty_inode

remove-PF_SYNC.patch

dont-inherit-mlockall.patch
  Don't inherit mm->def_flags across forks

bootmem-alloc-alignment.patch
  bootmem allocator merging fix

ext23_free_blocks-check.patch
  ext2/ext3_free_blocks() extra check

blkdev-rlimit.patch
  don't allpy file size rlimits to blockdevs

readahead-pinned-memory.patch
  limit pinned memory due to readahead

page-walk-api.patch

page-walk-scsi.patch

page-walk-api-update.patch
  pagewalk API update

^ permalink raw reply	[flat|nested] 22+ messages in thread
* [PATCH] CFQ scheduler, #2
@ 2003-02-14 14:19 Jens Axboe
  2003-02-14 14:51 ` Jens Axboe
  2003-02-15 10:00 ` Mike Galbraith
  0 siblings, 2 replies; 22+ messages in thread
From: Jens Axboe @ 2003-02-14 14:19 UTC (permalink / raw)
  To: Linux Kernel

Hi,

The version posted the other day did fair queueing of requests between
processes, but it did not help to provide fair request allocation. This
version does that too, results are rather remarkable. In addition, the
following changes were made:

- Fix lost request problem with rbtree aliasing. The default io
  scheduler in 2.5.60 has the same bug, a fix has been sent separetely
  to Linus that addresses this.

- Add front merging.

- Missing queue_lock grab in get_request_wait() before checking request
  list count. Again, a generic kernel bug. A patch will be sent to Linus
  to address that as well.

Obligatory contest results.

no_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   31      177.4   0       0.0     1.00
2.5.60-cfq-fr2      1   31      177.4   0       0.0     1.00
2.5.60-mm1          2   32      171.9   0       0.0     1.00
cacherun:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   29      182.8   0       0.0     0.94
2.5.60-cfq-fr2      1   29      182.8   0       0.0     0.94
2.5.60-mm1          2   29      186.2   0       0.0     0.91
process_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   38      142.1   12      47.4    1.23
2.5.60-cfq-fr2      1   43      123.3   20      67.4    1.39
2.5.60-mm1          2   38      142.1   13      50.0    1.19
ctar_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   38      147.4   0       0.0     1.23
2.5.60-cfq-fr2      1   37      151.4   0       0.0     1.19
2.5.60-mm1          2   36      155.6   0       0.0     1.12
xtar_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   40      140.0   0       2.5     1.29
2.5.60-cfq-fr2      1   37      148.6   0       2.6     1.19
2.5.60-mm1          2   39      143.6   0       2.6     1.22
io_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   93      61.3    2       14.0    3.00
2.5.60-cfq-fr2      1   73      76.7    1       9.8     2.35
2.5.60-mm1          2   82      69.5    1       9.8     2.56
read_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   40      140.0   0       5.0     1.29
2.5.60-cfq-fr2      1   40      140.0   0       5.0     1.29
2.5.60-mm1          2   38      147.4   0       2.6     1.19
list_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   35      157.1   0       8.6     1.13
2.5.60-cfq-fr2      1   35      160.0   0       11.4    1.13
2.5.60-mm1          2   34      164.7   0       8.8     1.06
mem_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   50      116.0   75      10.0    1.61
2.5.60-cfq-fr2      1   57      100.0   81      8.8     1.84
2.5.60-mm1          2   52      113.5   77      9.4     1.62
dbench_load:
Kernel         [runs]   Time    CPU%    Loads   LCPU%   Ratio
2.5.60              2   36      155.6   12693   27.8    1.16
2.5.60-mm1          2   35      160.0   12486   28.6    1.09


Patch is against 2.5.60-BK.

===== drivers/block/Makefile 1.14 vs edited =====
--- 1.14/drivers/block/Makefile	Mon Feb  3 23:19:36 2003
+++ edited/drivers/block/Makefile	Tue Feb 11 09:35:55 2003
@@ -8,7 +8,8 @@
 # In the future, some of these should be built conditionally.
 #
 
-obj-y	:= elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o deadline-iosched.o
+obj-y	:= elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o \
+	    deadline-iosched.o cfq-iosched.o
 
 obj-$(CONFIG_MAC_FLOPPY)	+= swim3.o
 obj-$(CONFIG_BLK_DEV_FD)	+= floppy.o
===== drivers/block/elevator.c 1.37 vs edited =====
--- 1.37/drivers/block/elevator.c	Tue Jan 14 23:59:43 2003
+++ edited/drivers/block/elevator.c	Fri Feb 14 14:08:15 2003
@@ -408,6 +408,16 @@
 	return NULL;
 }
 
+int elv_may_queue(request_queue_t *q, int rw)
+{
+	elevator_t *e = &q->elevator;
+
+	if (e->elevator_may_queue_fn)
+		return e->elevator_may_queue_fn(q, rw);
+
+	return 1;
+}
+
 int elv_register_queue(struct gendisk *disk)
 {
 	request_queue_t *q = disk->queue;
===== drivers/block/ll_rw_blk.c 1.151 vs edited =====
--- 1.151/drivers/block/ll_rw_blk.c	Thu Feb 13 05:02:43 2003
+++ edited/drivers/block/ll_rw_blk.c	Fri Feb 14 14:56:45 2003
@@ -45,7 +45,7 @@
  * Number of requests per queue.  This many for reads and for writes (twice
  * this number, total).
  */
-static int queue_nr_requests;
+int queue_nr_requests;
 
 /*
  * How many free requests must be available before we wake a process which
@@ -1283,7 +1283,7 @@
 	if (blk_init_free_list(q))
 		return -ENOMEM;
 
-	if ((ret = elevator_init(q, &iosched_deadline))) {
+	if ((ret = elevator_init(q, &iosched_cfq))) {
 		blk_cleanup_queue(q);
 		return ret;
 	}
@@ -1320,7 +1320,7 @@
 	struct request *rq = NULL;
 	struct request_list *rl = q->rq + rw;
 
-	if (!list_empty(&rl->free)) {
+	if (!list_empty(&rl->free) && elv_may_queue(q, rw)) {
 		rq = blkdev_free_rq(&rl->free);
 		list_del_init(&rq->queuelist);
 		rq->ref_count = 1;
@@ -1358,11 +1358,19 @@
 
 	generic_unplug_device(q);
 	do {
+		int block = 0;
+
 		prepare_to_wait_exclusive(&rl->wait, &wait,
 					TASK_UNINTERRUPTIBLE);
-		if (!rl->count)
+		spin_lock_irq(q->queue_lock);
+		if (!rl->count || !elv_may_queue(q, rw))
+			block = 1;
+		spin_unlock_irq(q->queue_lock);
+
+		if (block)
 			io_schedule();
 		finish_wait(&rl->wait, &wait);
+
 		spin_lock_irq(q->queue_lock);
 		rq = get_request(q, rw);
 		spin_unlock_irq(q->queue_lock);
===== include/linux/elevator.h 1.18 vs edited =====
--- 1.18/include/linux/elevator.h	Sun Jan 12 15:10:40 2003
+++ edited/include/linux/elevator.h	Fri Feb 14 14:07:45 2003
@@ -15,6 +15,7 @@
 typedef void (elevator_remove_req_fn) (request_queue_t *, struct request *);
 typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *);
 typedef struct list_head *(elevator_get_sort_head_fn) (request_queue_t *, struct request *);
+typedef int (elevator_may_queue_fn) (request_queue_t *, int);
 
 typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
 typedef void (elevator_exit_fn) (request_queue_t *, elevator_t *);
@@ -34,6 +35,8 @@
 	elevator_request_list_fn *elevator_former_req_fn;
 	elevator_request_list_fn *elevator_latter_req_fn;
 
+	elevator_may_queue_fn *elevator_may_queue_fn;
+
 	elevator_init_fn *elevator_init_fn;
 	elevator_exit_fn *elevator_exit_fn;
 
@@ -58,6 +61,7 @@
 extern struct request *elv_latter_request(request_queue_t *, struct request *);
 extern int elv_register_queue(struct gendisk *);
 extern void elv_unregister_queue(struct gendisk *);
+extern int elv_may_queue(request_queue_t *, int);
 
 #define __elv_add_request_pos(q, rq, pos)	\
 	(q)->elevator.elevator_add_req_fn((q), (rq), (pos))
@@ -72,6 +76,8 @@
  * starvation
  */
 extern elevator_t iosched_deadline;
+
+extern elevator_t iosched_cfq;
 
 extern int elevator_init(request_queue_t *, elevator_t *);
 extern void elevator_exit(request_queue_t *);
--- /dev/null	2003-01-19 21:08:59.000000000 +0100
+++ linux-2.5-sfq/drivers/block/cfq-iosched.c	2003-02-14 15:06:05.000000000 +0100
@@ -0,0 +1,699 @@
+/*
+ *  linux/drivers/block/cfq-iosched.c
+ *
+ *  CFQ, or complete fairness queueing, disk scheduler.
+ *
+ *  Based on ideas from a previously unfinished io
+ *  scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
+ *
+ *  Copyright (C) 2003 Jens Axboe <axboe@suse.de>
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
+#include <linux/bio.h>
+#include <linux/blk.h>
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/hash.h>
+#include <linux/rbtree.h>
+#include <linux/mempool.h>
+
+/*
+ * tunables
+ */
+static int cfq_quantum = 4;
+static int cfq_queued = 8;
+
+#define CFQ_QHASH_SHIFT		6
+#define CFQ_QHASH_ENTRIES	(1 << CFQ_QHASH_SHIFT)
+#define list_entry_qhash(entry)	list_entry((entry), struct cfq_queue, cfq_hash)
+
+#define CFQ_MHASH_SHIFT		8
+#define CFQ_MHASH_BLOCK(sec)	((sec) >> 3)
+#define CFQ_MHASH_ENTRIES	(1 << CFQ_MHASH_SHIFT)
+#define CFQ_MHASH_FN(sec)	(hash_long(CFQ_MHASH_BLOCK((sec)),CFQ_MHASH_SHIFT))
+#define ON_MHASH(crq)		!list_empty(&(crq)->hash)
+#define rq_hash_key(rq)		((rq)->sector + (rq)->nr_sectors)
+#define list_entry_hash(ptr)	list_entry((ptr), struct cfq_rq, hash)
+
+#define list_entry_cfqq(ptr)	list_entry((ptr), struct cfq_queue, cfq_list)
+
+#define RQ_DATA(rq)		((struct cfq_rq *) (rq)->elevator_private)
+
+static kmem_cache_t *crq_pool;
+static kmem_cache_t *cfq_pool;
+static mempool_t *cfq_mpool;
+
+struct cfq_queue {
+	struct list_head cfq_hash;
+	struct list_head cfq_list;
+	struct rb_root sort_list;
+	int pid;
+	int queued[2];
+#if 0
+	/*
+	 * with a simple addition like this, we can do io priorities. almost.
+	 * does need a split request free list, too.
+	 */
+	int io_prio
+#endif
+};
+
+struct cfq_data {
+	struct list_head rr_list;
+	struct list_head *dispatch;
+	struct list_head *cfq_hash;
+
+	struct list_head *crq_hash;
+
+	int busy_queues;
+
+	unsigned long random_seed;
+};
+
+struct cfq_rq {
+	struct rb_node rb_node;
+	sector_t rb_key;
+
+	struct request *request;
+
+	struct cfq_queue *cfq_queue;
+
+	struct list_head hash;
+};
+
+static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq);
+static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid);
+static void cfq_dispatch_sort(struct list_head *head, struct cfq_rq *crq);
+
+/*
+ * lots of deadline iosched dupes, can be abstracted later...
+ */
+static inline void __cfq_del_crq_hash(struct cfq_rq *crq)
+{
+	list_del_init(&crq->hash);
+}
+
+static inline void cfq_del_crq_hash(struct cfq_rq *crq)
+{
+	if (ON_MHASH(crq))
+		__cfq_del_crq_hash(crq);
+}
+
+static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
+{
+	struct request *rq = crq->request;
+
+	BUG_ON(ON_MHASH(crq));
+
+	list_add(&crq->hash, &cfqd->crq_hash[CFQ_MHASH_FN(rq_hash_key(rq))]);
+}
+
+static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
+{
+	struct list_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)];
+	struct list_head *entry, *next = hash_list->next;
+
+	while ((entry = next) != hash_list) {
+		struct cfq_rq *crq = list_entry_hash(entry);
+		struct request *__rq = crq->request;
+
+		next = entry->next;
+		
+		BUG_ON(!ON_MHASH(crq));
+
+		if (!rq_mergeable(__rq)) {
+			__cfq_del_crq_hash(crq);
+			continue;
+		}
+
+		if (rq_hash_key(__rq) == offset)
+			return __rq;
+	}
+
+	return NULL;
+}
+
+/*
+ * rb tree support functions
+ */
+#define RB_EMPTY(root)	((root)->rb_node == NULL)
+#define RB_CLEAR(root)	((root)->rb_node = NULL)
+#define ON_RB(crq)	((crq)->cfq_queue != NULL)
+#define rb_entry_crq(node)	rb_entry((node), struct cfq_rq, rb_node)
+#define rq_rb_key(rq)		(rq)->sector
+
+static inline void cfq_del_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
+{
+	if (ON_RB(crq)) {
+		rb_erase(&crq->rb_node, &cfqq->sort_list);
+		crq->cfq_queue = NULL;
+	}
+}
+
+static struct cfq_rq *
+__cfq_add_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
+{
+	struct rb_node **p = &cfqq->sort_list.rb_node;
+	struct rb_node *parent = NULL;
+	struct cfq_rq *__crq;
+
+	while (*p) {
+		parent = *p;
+		__crq = rb_entry_crq(parent);
+
+		if (crq->rb_key < __crq->rb_key)
+			p = &(*p)->rb_left;
+		else if (crq->rb_key > __crq->rb_key)
+			p = &(*p)->rb_right;
+		else
+			return __crq;
+	}
+
+	rb_link_node(&crq->rb_node, parent, p);
+	return 0;
+}
+
+static void
+cfq_add_crq_rb(struct cfq_data *cfqd, struct cfq_queue *cfqq,struct cfq_rq *crq)
+{
+	struct request *rq = crq->request;
+	struct cfq_rq *__alias;
+
+	crq->rb_key = rq_rb_key(rq);
+
+retry:
+	__alias = __cfq_add_crq_rb(cfqq, crq);
+	if (!__alias) {
+		rb_insert_color(&crq->rb_node, &cfqq->sort_list);
+		crq->cfq_queue = cfqq;
+		cfqq->queued[rq_data_dir(rq)]++;
+		return;
+	}
+
+	cfq_del_crq_rb(cfqq, __alias);
+	cfq_dispatch_sort(cfqd->dispatch, __alias);
+	goto retry;
+}
+
+static struct request *
+cfq_find_rq_rb(struct cfq_data *cfqd, sector_t sector)
+{
+	struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, current->pid);
+	struct rb_node *n;
+
+	if (!cfqq)
+		goto out;
+
+	n = cfqq->sort_list.rb_node;
+	while (n) {
+		struct cfq_rq *crq = rb_entry_crq(n);
+
+		if (sector < crq->rb_key)
+			n = n->rb_left;
+		else if (sector > crq->rb_key)
+			n = n->rb_right;
+		else
+			return crq->request;
+	}
+
+out:
+	return NULL;
+}
+
+static void cfq_remove_request(request_queue_t *q, struct request *rq)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct cfq_rq *crq = RQ_DATA(rq);
+
+	if (crq) {
+		struct cfq_queue *cfqq = crq->cfq_queue;
+
+		cfq_del_crq_hash(crq);
+
+		if (cfqq) {
+			cfq_del_crq_rb(cfqq, crq);
+
+			if (RB_EMPTY(&cfqq->sort_list))
+				cfq_put_queue(cfqd, cfqq);
+		}
+	}
+
+	if (&rq->queuelist == q->last_merge)
+		q->last_merge = NULL;
+
+	list_del_init(&rq->queuelist);
+}
+
+static int
+cfq_merge(request_queue_t *q, struct list_head **insert, struct bio *bio)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct request *__rq;
+	int ret;
+
+	ret = elv_try_last_merge(q, bio);
+	if (ret != ELEVATOR_NO_MERGE) {
+		__rq = list_entry_rq(q->last_merge);
+		goto out_insert;
+	}
+
+	__rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
+	if (__rq) {
+		BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector);
+
+		if (elv_rq_merge_ok(__rq, bio)) {
+			ret = ELEVATOR_BACK_MERGE;
+			goto out;
+		}
+	}
+
+	__rq = cfq_find_rq_rb(cfqd, bio->bi_sector + bio_sectors(bio));
+	if (__rq) {
+		if (elv_rq_merge_ok(__rq, bio)) {
+			ret = ELEVATOR_FRONT_MERGE;
+			goto out;
+		}
+	}
+
+	return ELEVATOR_NO_MERGE;
+out:
+	q->last_merge = &__rq->queuelist;
+out_insert:
+	*insert = &__rq->queuelist;
+	return ret;
+}
+
+static void cfq_merged_request(request_queue_t *q, struct request *req)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct cfq_rq *crq = RQ_DATA(req);
+
+	cfq_del_crq_hash(crq);
+	cfq_add_crq_hash(cfqd, crq);
+
+	if (ON_RB(crq) && rq_rb_key(req) != crq->rb_key) {
+		struct cfq_queue *cfqq = crq->cfq_queue;
+
+		cfq_del_crq_rb(cfqq, crq);
+		cfq_add_crq_rb(cfqd, cfqq, crq);
+	}
+
+	q->last_merge = &req->queuelist;
+}
+
+static void
+cfq_merged_requests(request_queue_t *q, struct request *req,
+		    struct request *next)
+{
+	cfq_merged_request(q, req);
+	cfq_remove_request(q, next);
+}
+
+static void cfq_dispatch_sort(struct list_head *head, struct cfq_rq *crq)
+{
+	struct list_head *entry = head;
+	struct request *__rq;
+
+	if (!list_empty(head)) {
+		__rq = list_entry_rq(head->next);
+
+		if (crq->request->sector < __rq->sector) {
+			entry = head->prev;
+			goto link;
+		}
+	}
+
+	while ((entry = entry->prev) != head) {
+		__rq = list_entry_rq(entry);
+
+		if (crq->request->sector <= __rq->sector)
+			break;
+	}
+
+link:
+	list_add_tail(&crq->request->queuelist, entry);
+}
+
+static inline void
+__cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+	struct cfq_rq *crq;
+
+	crq = rb_entry_crq(rb_first(&cfqq->sort_list));
+
+	cfq_del_crq_rb(cfqq, crq);
+	cfq_dispatch_sort(cfqd->dispatch, crq);
+}
+
+static int cfq_dispatch_requests(struct cfq_data *cfqd)
+{
+	struct cfq_queue *cfqq;
+	struct list_head *entry, *tmp;
+	int ret, queued, good_queues;
+
+	if (list_empty(&cfqd->rr_list))
+		return 0;
+
+	queued = ret = 0;
+restart:
+	good_queues = 0;
+	list_for_each_safe(entry, tmp, &cfqd->rr_list) {
+		cfqq = list_entry_cfqq(cfqd->rr_list.next);
+
+		BUG_ON(RB_EMPTY(&cfqq->sort_list));
+
+		__cfq_dispatch_requests(cfqd, cfqq);
+
+		if (RB_EMPTY(&cfqq->sort_list))
+			cfq_put_queue(cfqd, cfqq);
+		else
+			good_queues++;
+
+		queued++;
+		ret = 1;
+	}
+
+	if ((queued < cfq_quantum) && good_queues)
+		goto restart;
+
+	return ret;
+}
+
+static struct request *cfq_next_request(request_queue_t *q)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct request *rq;
+
+	if (!list_empty(cfqd->dispatch)) {
+		struct cfq_rq *crq;
+dispatch:
+		rq = list_entry_rq(cfqd->dispatch->next);
+
+		if (q->last_merge == &rq->queuelist)
+			q->last_merge = NULL;
+
+		crq = RQ_DATA(rq);
+		if (crq)
+			cfq_del_crq_hash(crq);
+
+		return rq;
+	}
+
+	if (cfq_dispatch_requests(cfqd))
+		goto dispatch;
+
+	return NULL;
+}
+
+static inline struct cfq_queue *
+__cfq_find_cfq_hash(struct cfq_data *cfqd, int pid, const int hashval)
+{
+	struct list_head *hash_list = &cfqd->cfq_hash[hashval];
+	struct list_head *entry;
+
+	list_for_each(entry, hash_list) {
+		struct cfq_queue *__cfqq = list_entry_qhash(entry);
+
+		if (__cfqq->pid == pid)
+			return __cfqq;
+	}
+
+	return NULL;
+}
+
+static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid)
+{
+	const int hashval = hash_long(current->pid, CFQ_QHASH_SHIFT);
+
+	return __cfq_find_cfq_hash(cfqd, pid, hashval);
+}
+
+static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+	cfqd->busy_queues--;
+	list_del(&cfqq->cfq_list);
+	list_del(&cfqq->cfq_hash);
+	mempool_free(cfqq, cfq_mpool);
+}
+
+static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, int pid)
+{
+	const int hashval = hash_long(current->pid, CFQ_QHASH_SHIFT);
+	struct cfq_queue *cfqq = __cfq_find_cfq_hash(cfqd, pid, hashval);
+
+	if (!cfqq) {
+		cfqq = mempool_alloc(cfq_mpool, GFP_NOIO);
+
+		INIT_LIST_HEAD(&cfqq->cfq_hash);
+		INIT_LIST_HEAD(&cfqq->cfq_list);
+		RB_CLEAR(&cfqq->sort_list);
+
+		cfqq->pid = pid;
+		cfqq->queued[0] = cfqq->queued[1] = 0;
+		list_add(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]);
+	}
+
+	return cfqq;
+}
+
+static void cfq_enqueue(struct cfq_data *cfqd, struct cfq_rq *crq)
+{
+	struct cfq_queue *cfqq;
+
+	cfqq = cfq_get_queue(cfqd, current->pid);
+
+	cfq_add_crq_rb(cfqd, cfqq, crq);
+
+	if (list_empty(&cfqq->cfq_list)) {
+		list_add(&cfqq->cfq_list, &cfqd->rr_list);
+		cfqd->busy_queues++;
+	}
+}
+
+static void
+cfq_insert_request(request_queue_t *q, struct request *rq,
+		   struct list_head *insert_here)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct cfq_rq *crq = RQ_DATA(rq);
+
+	if (unlikely(!blk_fs_request(rq))) {
+		if (!insert_here)
+			insert_here = cfqd->dispatch->prev;
+
+		list_add(&rq->queuelist, insert_here);
+		return;
+	}
+
+	if (rq_mergeable(rq)) {
+		cfq_add_crq_hash(cfqd, crq);
+
+		if (!q->last_merge)
+			q->last_merge = &rq->queuelist;
+	}
+
+	cfq_enqueue(cfqd, crq);
+}
+
+static int cfq_queue_empty(request_queue_t *q)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+
+	if (list_empty(cfqd->dispatch) && list_empty(&cfqd->rr_list))
+		return 1;
+
+	return 0;
+}
+
+static struct request *
+cfq_former_request(request_queue_t *q, struct request *rq)
+{
+	struct cfq_rq *crq = RQ_DATA(rq);
+	struct rb_node *rbprev = rb_prev(&crq->rb_node);
+
+	if (rbprev)
+		return rb_entry_crq(rbprev)->request;
+
+	return NULL;
+}
+
+static struct request *
+cfq_latter_request(request_queue_t *q, struct request *rq)
+{
+	struct cfq_rq *crq = RQ_DATA(rq);
+	struct rb_node *rbnext = rb_next(&crq->rb_node);
+
+	if (rbnext)
+		return rb_entry_crq(rbnext)->request;
+
+	return NULL;
+}
+
+extern int queue_nr_requests;
+
+static int cfq_may_queue(request_queue_t *q, int rw)
+{
+	struct cfq_data *cfqd = q->elevator.elevator_data;
+	struct cfq_queue *cfqq;
+	int limit, ret = 1;
+
+	if (!cfqd->busy_queues)
+		goto out;
+
+	cfqq = cfq_find_cfq_hash(cfqd, current->pid);
+	if (!cfqq)
+		goto out;
+
+	if (cfqq->queued[rw] < cfq_queued)
+		goto out;
+
+	limit = (queue_nr_requests - cfq_queued) / cfqd->busy_queues;
+	if (cfqq->queued[rw] > limit)
+		ret = 0;
+
+out:
+	return ret;
+}
+
+static void cfq_exit(request_queue_t *q, elevator_t *e)
+{
+	struct cfq_data *cfqd = e->elevator_data;
+	struct cfq_rq *crq;
+	struct request *rq;
+	int i;
+
+	for (i = READ; i <= WRITE; i++) {
+		struct request_list *rl = &q->rq[i];
+		struct list_head *entry;
+
+		list_for_each(entry, &rl->free) {
+			rq = list_entry_rq(entry);
+
+			crq = RQ_DATA(rq);
+			if (!crq)
+				continue;
+
+			rq->elevator_private = NULL;
+			kmem_cache_free(crq_pool, crq);
+		}
+	}
+
+	e->elevator_data = NULL;
+	kfree(cfqd->crq_hash);
+	kfree(cfqd->cfq_hash);
+	kfree(cfqd);
+}
+
+static void *slab_pool_alloc(int gfp_mask, void *data)
+{
+	return kmem_cache_alloc(data, gfp_mask);
+}
+
+static void slab_pool_free(void *ptr, void *data)
+{
+	kmem_cache_free(data, ptr);
+}
+
+static int cfq_init(request_queue_t *q, elevator_t *e)
+{
+	struct cfq_data *cfqd;
+	struct request *rq;
+	struct cfq_rq *crq;
+	int i, ret = 0;
+
+	cfqd = kmalloc(sizeof(*cfqd), GFP_KERNEL);
+	if (!cfqd)
+		return -ENOMEM;
+
+	memset(cfqd, 0, sizeof(*cfqd));
+	INIT_LIST_HEAD(&cfqd->rr_list);
+
+	cfqd->crq_hash = kmalloc(sizeof(struct list_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL);
+	if (!cfqd->crq_hash)
+		goto out_crqhash;
+
+	cfqd->cfq_hash = kmalloc(sizeof(struct list_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL);
+	if (!cfqd->cfq_hash)
+		goto out_cfqhash;
+
+	for (i = 0; i < CFQ_MHASH_ENTRIES; i++)
+		INIT_LIST_HEAD(&cfqd->crq_hash[i]);
+	for (i = 0; i < CFQ_QHASH_ENTRIES; i++)
+		INIT_LIST_HEAD(&cfqd->cfq_hash[i]);
+
+	for (i = READ; i <= WRITE; i++) {
+		struct request_list *rl = &q->rq[i];
+		struct list_head *entry;
+
+		list_for_each(entry, &rl->free) {
+			rq = list_entry_rq(entry);
+
+			crq = kmem_cache_alloc(crq_pool, GFP_KERNEL);
+			if (!crq) {
+				ret = -ENOMEM;
+				break;
+			}
+
+			memset(crq, 0, sizeof(*crq));
+			INIT_LIST_HEAD(&crq->hash);
+			crq->request = rq;
+			rq->elevator_private = crq;
+		}
+	}
+
+	cfqd->dispatch = &q->queue_head;
+	e->elevator_data = cfqd;
+	return ret;
+out_cfqhash:
+	kfree(cfqd->crq_hash);
+out_crqhash:
+	kfree(cfqd);
+	return -ENOMEM;
+}
+
+static int __init cfq_slab_setup(void)
+{
+	crq_pool = kmem_cache_create("crq_pool", sizeof(struct cfq_rq), 0, 0,
+					NULL, NULL);
+
+	if (!crq_pool)
+		panic("cfq_iosched: can't init crq pool\n");
+
+	cfq_pool = kmem_cache_create("cfq_pool", sizeof(struct cfq_queue), 0, 0,
+					NULL, NULL);
+
+	if (!cfq_pool)
+		panic("cfq_iosched: can't init cfq pool\n");
+
+	cfq_mpool = mempool_create(64, slab_pool_alloc, slab_pool_free, cfq_pool);
+
+	if (!cfq_mpool)
+		panic("cfq_iosched: can't init cfq mpool\n");
+
+	return 0;
+}
+
+subsys_initcall(cfq_slab_setup);
+
+elevator_t iosched_cfq = {
+	.elevator_merge_fn = 		cfq_merge,
+	.elevator_merged_fn =		cfq_merged_request,
+	.elevator_merge_req_fn =	cfq_merged_requests,
+	.elevator_next_req_fn =		cfq_next_request,
+	.elevator_add_req_fn =		cfq_insert_request,
+	.elevator_remove_req_fn =	cfq_remove_request,
+	.elevator_queue_empty_fn =	cfq_queue_empty,
+	.elevator_former_req_fn =	cfq_former_request,
+	.elevator_latter_req_fn =	cfq_latter_request,
+	.elevator_may_queue_fn =	cfq_may_queue,
+	.elevator_init_fn =		cfq_init,
+	.elevator_exit_fn =		cfq_exit,
+};
+
+EXPORT_SYMBOL(iosched_cfq);

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 22+ messages in thread
end of thread, other threads:[~2003-02-18 12:44 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2002-12-09  8:26 2.5.50-mm2 Andrew Morton
2002-12-13 22:55 ` 2.5.50-mm2 Christoph Hellwig
2002-12-13 19:58   ` 2.5.50-mm2 Andrew Morton
     [not found] ` <200212092059.06287.tomlins@cam.org>
     [not found]   ` <3DF54BD7.726993D@digeo.com>
2003-02-05  4:41     ` [PATCH] let kernel find QT in latest debian sid Ed Tomlinson
2003-02-11 13:13     ` [BUG] link error in usbserial with gcc3.2 Ed Tomlinson
2003-02-12  1:59       ` Ed Tomlinson
2003-02-18  5:51         ` Greg KH
2003-02-18 12:50           ` Ed Tomlinson
2003-02-13 13:18     ` [PATCH] (0-2) governors for 60-bk Ed Tomlinson
2003-02-14 21:38     ` [PATCH] CFQ scheduler, #2 Ed Tomlinson
2003-02-15  8:33       ` Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2003-02-14 14:19 Jens Axboe
2003-02-14 14:51 ` Jens Axboe
2003-02-15 10:00 ` Mike Galbraith
2003-02-15 11:22   ` Rik van Riel
2003-02-15 16:35     ` Jens Axboe
2003-02-16  6:24       ` Mike Galbraith
     [not found]   ` <Pine.LNX.4.50L.0302150920510.16301-100000@imladris.surriel .com>
2003-02-15 11:40     ` Mike Galbraith
2003-02-15 11:49       ` Rik van Riel
2003-02-15 12:01         ` William Lee Irwin III
     [not found]       ` <Pine.LNX.4.50L.0302150947570.20371-100000@imladris.surriel .com>
2003-02-15 12:07         ` Mike Galbraith
2003-02-15 16:00           ` Mike Galbraith

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