Jens Axboe 1e42807918 block: reduce stack footprint of blk_recount_segments() ... blk_recalc_rq_segments() requires a request structure passed in, which we don't have from blk_recount_segments(). So the latter allocates one on the stack, using > 400 bytes of stack for that. This can cause us to spill over one page of stack from ext4 at least: 0) 4560 400 blk_recount_segments+0x43/0x62 1) 4160 32 bio_phys_segments+0x1c/0x24 2) 4128 32 blk_rq_bio_prep+0x2a/0xf9 3) 4096 32 init_request_from_bio+0xf9/0xfe 4) 4064 112 __make_request+0x33c/0x3f6 5) 3952 144 generic_make_request+0x2d1/0x321 6) 3808 64 submit_bio+0xb9/0xc3 7) 3744 48 submit_bh+0xea/0x10e 8) 3696 368 ext4_mb_init_cache+0x257/0xa6a [ext4] 9) 3328 288 ext4_mb_regular_allocator+0x421/0xcd9 [ext4] 10) 3040 160 ext4_mb_new_blocks+0x211/0x4b4 [ext4] 11) 2880 336 ext4_ext_get_blocks+0xb61/0xd45 [ext4] 12) 2544 96 ext4_get_blocks_wrap+0xf2/0x200 [ext4] 13) 2448 80 ext4_da_get_block_write+0x6e/0x16b [ext4] 14) 2368 352 mpage_da_map_blocks+0x7e/0x4b3 [ext4] 15) 2016 352 ext4_da_writepages+0x2ce/0x43c [ext4] 16) 1664 32 do_writepages+0x2d/0x3c 17) 1632 144 __writeback_single_inode+0x162/0x2cd 18) 1488 96 generic_sync_sb_inodes+0x1e3/0x32b 19) 1392 16 sync_sb_inodes+0xe/0x10 20) 1376 48 writeback_inodes+0x69/0xb3 21) 1328 208 balance_dirty_pages_ratelimited_nr+0x187/0x2f9 22) 1120 224 generic_file_buffered_write+0x1d4/0x2c4 23) 896 176 __generic_file_aio_write_nolock+0x35f/0x393 24) 720 80 generic_file_aio_write+0x6c/0xc8 25) 640 80 ext4_file_write+0xa9/0x137 [ext4] 26) 560 320 do_sync_write+0xf0/0x137 27) 240 48 vfs_write+0xb3/0x13c 28) 192 64 sys_write+0x4c/0x74 29) 128 128 system_call_fastpath+0x16/0x1b Split the segment counting out into a __blk_recalc_rq_segments() helper to avoid allocating an onstack request just for checking the physical segment count. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>		2009-02-26 10:45:48 +01:00
..
Kconfig	block: Add Kconfig help which notes that ext4 needs CONFIG_LBD	2009-01-06 15:16:33 -05:00
Kconfig.iosched	…
Makefile	…
as-iosched.c	block: get rid of elevator_t typedef	2008-12-29 08:29:50 +01:00
blk-barrier.c	block: Fix documentation for blkdev_issue_flush()	2009-01-30 12:34:37 +01:00
blk-core.c	block: fix oops in blk_queue_io_stat()	2009-02-02 08:42:32 +01:00
blk-exec.c	…
blk-integrity.c	block: Allow empty integrity profile	2009-01-30 12:34:36 +01:00
blk-ioc.c	…
blk-map.c	[SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITE	2009-01-02 11:10:35 -06:00
blk-merge.c	block: reduce stack footprint of blk_recount_segments()	2009-02-26 10:45:48 +01:00
blk-settings.c	block: use min_not_zero in blk_queue_stack_limits	2008-12-29 08:29:51 +01:00
blk-softirq.c	block: make blk_softirq_init() static	2008-12-29 08:29:51 +01:00
blk-sysfs.c	block: add sysfs file for controlling io stats accounting	2009-01-30 12:34:38 +01:00
blk-tag.c	block/blk-tag.c: cleanup kernel-doc	2008-12-29 08:28:43 +01:00
blk-timeout.c	block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list	2009-02-18 10:34:16 +01:00
blk.h	block: fix oops in blk_queue_io_stat()	2009-02-02 08:42:32 +01:00
blktrace.c	block: fix bad definition of BIO_RW_SYNC	2009-02-18 10:32:00 +01:00
bsg.c	bsg: Fix sense buffer bug in SG_IO	2009-02-18 10:32:00 +01:00
cfq-iosched.c	cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice	2009-01-30 12:47:33 +01:00
cmd-filter.c	…
compat_ioctl.c	block: don't take lock on changing ra_pages	2008-12-29 08:28:43 +01:00
deadline-iosched.c	block: get rid of elevator_t typedef	2008-12-29 08:29:50 +01:00
elevator.c	block: get rid of elevator_t typedef	2008-12-29 08:29:50 +01:00
genhd.c	block: add documentation for register_blkdev()	2009-02-26 10:45:48 +01:00
ioctl.c	block: don't take lock on changing ra_pages	2008-12-29 08:28:43 +01:00
noop-iosched.c	block: get rid of elevator_t typedef	2008-12-29 08:29:50 +01:00
scsi_ioctl.c	…