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authorHeiko Carstens <heiko.carstens@de.ibm.com>2008-10-28 11:10:21 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-10-28 11:12:06 +0100
commit7f5a8ba6b0297ca941f43f8f5cbf0e5c8c4dd916 (patch)
tree8077f6d850ce26d8a33e505238c5b4848c5a9c6d /arch
parent46e7951f9431b5e6bfbeb3044fdb4b522f58101c (diff)
downloadlinux-linaro-stable-7f5a8ba6b0297ca941f43f8f5cbf0e5c8c4dd916.tar.gz
[S390] No more 4kb stacks.
We got a stack overflow with a small stack configuration on a 32 bit system. It just looks like as 4kb isn't enough and too dangerous. So lets get rid of 4kb stacks on 32 bit. But one thing I completely dislike about the call trace below is that just for debugging or tracing purposes sprintf gets called (cio_start_key): /* process condition code */ sprintf(dbf_txt, "ccode:%d", ccode); CIO_TRACE_EVENT(4, dbf_txt); But maybe its just me who thinks that this could be done better. <4>Kernel stack overflow. <4>Modules linked in: dm_multipath sunrpc bonding qeth_l2 dm_mod qeth ccwgroup vmur <4>CPU: 1 Not tainted 2.6.27-30.x.20081015-s390default #1 <4>Process httpd (pid: 3807, task: 20ae2df8, ksp: 1666fb78) <4>Krnl PSW : 040c0000 8027098a (number+0xe/0x348) <4> R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 <4>Krnl GPRS: 00d43318 0027097c 1666f277 9666f270 <4> 00000000 00000000 0000000a ffffffff <4> 9666f270 1666f228 1666f277 1666f098 <4> 00000002 80270982 80271016 1666f098 <4>Krnl Code: 8027097e: f0340dd0a7f1 srp 3536(4,%r0),2033(%r10),4 <4> 80270984: 0f00 clcl %r0,%r0 <4> 80270986: a7840001 brc 8,80270988 <4> >8027098a: 18ef lr %r14,%r15 <4> 8027098c: a7faff68 ahi %r15,-152 <4> 80270990: 18bf lr %r11,%r15 <4> 80270992: 18a2 lr %r10,%r2 <4> 80270994: 1893 lr %r9,%r3 Modified calltrace with annotated stackframe size of each function: stackframe size | 0 304 vsnprintf+850 [0x271016] 1 72 sprintf+74 [0x271522] 2 56 cio_start_key+262 [0x2d4c16] 3 56 ccw_device_start_key+222 [0x2dfe92] 4 56 ccw_device_start+40 [0x2dff28] 5 48 raw3215_start_io+104 [0x30b0f8] 6 56 raw3215_write+494 [0x30ba0a] 7 40 con3215_write+68 [0x30bafc] 8 40 __call_console_drivers+146 [0x12b0fa] 9 32 _call_console_drivers+102 [0x12b192] 10 64 release_console_sem+268 [0x12b614] 11 168 vprintk+462 [0x12bca6] 12 72 printk+68 [0x12bfd0] 13 256 __print_symbol+50 [0x15a882] 14 56 __show_trace+162 [0x103d06] 15 32 show_trace+224 [0x103e70] 16 48 show_stack+152 [0x103f20] 17 56 dump_stack+126 [0x104612] 18 96 __alloc_pages_internal+592 [0x175004] 19 80 cache_alloc_refill+776 [0x196f3c] 20 40 __kmalloc+258 [0x1972ae] 21 40 __alloc_skb+94 [0x328086] 22 32 pskb_copy+50 [0x328252] 23 32 skb_realloc_headroom+110 [0x328a72] 24 104 qeth_l2_hard_start_xmit+378 [0x7803bfde] 25 56 dev_hard_start_xmit+450 [0x32ef6e] 26 56 __qdisc_run+390 [0x3425d6] 27 48 dev_queue_xmit+410 [0x331e06] 28 40 ip_finish_output+308 [0x354ac8] 29 56 ip_output+218 [0x355b6e] 30 24 ip_local_out+56 [0x354584] 31 120 ip_queue_xmit+300 [0x355cec] 32 96 tcp_transmit_skb+812 [0x367da8] 33 40 tcp_push_one+158 [0x369fda] 34 112 tcp_sendmsg+852 [0x35d5a0] 35 240 sock_sendmsg+164 [0x32035c] 36 56 kernel_sendmsg+86 [0x32064a] 37 88 sock_no_sendpage+98 [0x322b22] 38 104 tcp_sendpage+70 [0x35cc1e] 39 48 sock_sendpage+74 [0x31eb66] 40 64 pipe_to_sendpage+102 [0x1c4b2e] 41 64 __splice_from_pipe+120 [0x1c5340] 42 72 splice_from_pipe+90 [0x1c57e6] 43 56 generic_splice_sendpage+38 [0x1c5832] 44 48 do_splice_from+104 [0x1c4c38] 45 48 direct_splice_actor+52 [0x1c4c88] 46 80 splice_direct_to_actor+180 [0x1c4f80] 47 72 do_splice_direct+70 [0x1c5112] 48 64 do_sendfile+360 [0x19de18] 49 72 sys_sendfile64+126 [0x19df32] 50 336 sysc_do_restart+18 [0x111a1a] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/Kconfig14
-rw-r--r--arch/s390/include/asm/thread_info.h5
2 files changed, 6 insertions, 13 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 5f5c29269fb1..8116a3328a19 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -241,19 +241,17 @@ config PACK_STACK
Say Y if you are unsure.
config SMALL_STACK
- bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
- depends on PACK_STACK && !LOCKDEP
+ bool "Use 8kb for kernel stack instead of 16kb"
+ depends on PACK_STACK && 64BIT && !LOCKDEP
help
If you say Y here and the compiler supports the -mkernel-backchain
- option the kernel will use a smaller kernel stack size. For 31 bit
- the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
- instead of 16kb. This allows to run more thread on a system and
- reduces the pressure on the memory management for higher order
- page allocations.
+ option the kernel will use a smaller kernel stack size. The reduced
+ size is 8kb instead of 16kb. This allows to run more threads on a
+ system and reduces the pressure on the memory management for higher
+ order page allocations.
Say N if you are unsure.
-
config CHECK_STACK
bool "Detect kernel stack overflow"
help
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index de3fad60c682..c1eaf9604da7 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -15,13 +15,8 @@
* Size of kernel stack for each process
*/
#ifndef __s390x__
-#ifndef __SMALL_STACK
#define THREAD_ORDER 1
#define ASYNC_ORDER 1
-#else
-#define THREAD_ORDER 0
-#define ASYNC_ORDER 0
-#endif
#else /* __s390x__ */
#ifndef __SMALL_STACK
#define THREAD_ORDER 2