linux/include
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
..
acpi ACPI: Enable bit 11 in _PDC to advertise hw coord 2009-02-07 00:41:14 -05:00
asm-arm
asm-frv FRV: __pte_to_swp_entry doesn't expand correctly 2009-02-17 14:05:30 -08:00
asm-generic Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-26 09:47:28 -08:00
asm-h8300
asm-m32r byteorder: make swab.h include asm/swab.h like a regular header 2009-01-14 19:56:50 -08:00
asm-mn10300 byteorder: make swab.h include asm/swab.h like a regular header 2009-01-14 19:56:50 -08:00
crypto crypto: shash - Fix tfm destruction 2009-02-05 16:51:25 +11:00
drm drm: disable encoders before re-routing them 2009-02-25 14:42:23 +10:00
keys
linux block: reduce stack footprint of blk_recount_segments() 2009-02-26 10:45:48 +01:00
math-emu
media Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2009-02-02 19:26:06 -08:00
mtd headers_check fix: mtd/inftl-user.h 2009-01-31 00:13:34 +05:30
net net: Kill skb_truesize_check(), it only catches false-positives. 2009-02-17 21:24:05 -08:00
pcmcia
rdma
rxrpc
scsi [SCSI] iscsi_tcp: make padbuf non-static 2009-01-13 10:41:34 -06:00
sound headers_check fix: sound/hdsp.h 2009-01-31 00:13:56 +05:30
trace
video atyfb: fix CONFIG_ namespace violations 2009-02-05 12:56:48 -08:00
xen xen: add xenfs to allow usermode <-> Xen interaction 2009-01-08 08:30:59 -08:00
Kbuild