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您好, 在使用OMAPL138 evm过程中,我使用了MessageQ和ringIO来传输数据。利用ipcs -l ,情况如下:
* U! p' Y( p3 Jroot@tl:~# ipcs -l
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$ ?1 L9 J3 ?$ @9 Q0 J3 n------ Shared Memory Limits --------
9 ~2 P9 g; j$ R0 N! ~: i: C4 y) F; m9 }max number of segments = 4096
3 A$ P) y. b* f1 c# B \1 Hmax seg size (kbytes) = 32768- {& l+ d/ l* X5 _
max total shared memory (kbytes) = 8388608( J* E' `" M/ g: p/ {9 H
min seg size (bytes) = 1! i: `( f! k! c! N: p. o6 P( e7 ^
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------ Semaphore Limits --------
- r( p- X7 B8 s0 h& G& m/ gmax number of arrays = 128
) {7 R& s& I5 m0 O |( Ymax semaphores per array = 2506 b3 n/ `: a$ O' i0 k
max semaphores system wide = 32000; ` s D4 B4 }8 t
max ops per semop call = 328 @7 Y) ^, L7 b; |# p( @2 P" d- H
semaphore max value = 32767
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------ Messages Limits --------7 g$ ^7 v! G% L' \
max queues system wide = 1784 g- T# y' T: B6 ?; C# e
max size of message (bytes) = 8192. f4 ]2 {8 K' z) \" [0 n- A4 f
default max size of queue (bytes) = 16384
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但是,用ipcs -a . m* y1 m2 R! F `; e7 f; q
root@tl:~# ipcs -a
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------ Shared Memory Segments -------- v x$ Z( Q) h- V% ~
key shmid owner perms bytes nattch status ) J# @- h/ U9 h7 k
0x00000000 0 root 600 1024 1 dest ' w* z/ `+ X# X! m
0x00000000 196609 root 600 1024 1 dest 7 G! `4 Y! E& B$ M2 p: D z& l
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------ Semaphore Arrays --------* w. J' F0 x+ ]6 N. \
key semid owner perms nsems
/ b( f5 [4 @1 h& c5 D0x6411074d 0 root 600 1 . y3 r) L' Q" y+ J+ [- {
0x64110957 163841 root 600 1 & r0 @9 d, b8 w7 Y' w
0x641109a1 196610 root 600 1 4 y2 x' g2 i9 n, r8 [1 U
5 v' Y/ @9 h7 b/ t% d. r------ Message Queues --------% ]' g! y g3 m5 t
key msqid owner perms used-bytes messages " a' b7 u7 A, p! r! D- o
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请问,我的共享内存使用大小为 (float *)ring_buffer_acquired(ad->buffer, 2320 * sizeof(float)*18); 远大于1024BYTE ,请问为什么?
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