Mercurial > hg > nginx-quic
annotate src/core/ngx_cpuinfo.c @ 6673:e4c1f5b32868
Event pipe: do not set file's thread_handler if not needed.
This fixes a problem with aio threads and sendfile with aio_write switched
off, as observed with range requests after fc72784b1f52 (1.9.13). Potential
problems with sendfile in threads were previously described in 9fd738b85fad,
and this seems to be one of them.
The problem occurred as file's thread_handler was set to NULL by event pipe
code after a sendfile thread task was scheduled. As a result, no sendfile
completion code was executed, and the same buffer was additionally sent
using non-threaded sendfile. Fix is to avoid modifying file's thread_handler
if aio_write is switched off.
Note that with "aio_write on" it is still possible that sendfile will use
thread_handler as set by event pipe. This is believed to be safe though,
as handlers used are compatible.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 01 Sep 2016 20:05:23 +0300 |
parents | d620f497c50f |
children |
rev | line source |
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611 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4412 | 4 * Copyright (C) Nginx, Inc. |
611 | 5 */ |
6 | |
7 | |
8 #include <ngx_config.h> | |
9 #include <ngx_core.h> | |
10 | |
11 | |
12 #if (( __i386__ || __amd64__ ) && ( __GNUC__ || __INTEL_COMPILER )) | |
13 | |
14 | |
15 static ngx_inline void ngx_cpuid(uint32_t i, uint32_t *buf); | |
16 | |
17 | |
617 | 18 #if ( __i386__ ) |
19 | |
20 static ngx_inline void | |
21 ngx_cpuid(uint32_t i, uint32_t *buf) | |
22 { | |
23 | |
24 /* | |
25 * we could not use %ebx as output parameter if gcc builds PIC, | |
26 * and we could not save %ebx on stack, because %esp is used, | |
27 * when the -fomit-frame-pointer optimization is specified. | |
28 */ | |
29 | |
30 __asm__ ( | |
31 | |
32 " mov %%ebx, %%esi; " | |
33 | |
34 " cpuid; " | |
651 | 35 " mov %%eax, (%1); " |
36 " mov %%ebx, 4(%1); " | |
37 " mov %%edx, 8(%1); " | |
38 " mov %%ecx, 12(%1); " | |
617 | 39 |
40 " mov %%esi, %%ebx; " | |
41 | |
651 | 42 : : "a" (i), "D" (buf) : "ecx", "edx", "esi", "memory" ); |
617 | 43 } |
44 | |
45 | |
46 #else /* __amd64__ */ | |
47 | |
48 | |
611 | 49 static ngx_inline void |
50 ngx_cpuid(uint32_t i, uint32_t *buf) | |
51 { | |
52 uint32_t eax, ebx, ecx, edx; | |
53 | |
54 __asm__ ( | |
55 | |
56 "cpuid" | |
57 | |
58 : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (i) ); | |
59 | |
60 buf[0] = eax; | |
61 buf[1] = ebx; | |
62 buf[2] = edx; | |
63 buf[3] = ecx; | |
64 } | |
65 | |
66 | |
617 | 67 #endif |
68 | |
69 | |
611 | 70 /* auto detect the L2 cache line size of modern and widespread CPUs */ |
71 | |
72 void | |
73 ngx_cpuinfo(void) | |
74 { | |
75 u_char *vendor; | |
2613
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
|
76 uint32_t vbuf[5], cpu[4], model; |
611 | 77 |
78 vbuf[0] = 0; | |
79 vbuf[1] = 0; | |
80 vbuf[2] = 0; | |
81 vbuf[3] = 0; | |
82 vbuf[4] = 0; | |
83 | |
84 ngx_cpuid(0, vbuf); | |
85 | |
86 vendor = (u_char *) &vbuf[1]; | |
87 | |
88 if (vbuf[0] == 0) { | |
89 return; | |
90 } | |
91 | |
92 ngx_cpuid(1, cpu); | |
93 | |
94 if (ngx_strcmp(vendor, "GenuineIntel") == 0) { | |
95 | |
1871
9afb84c7cc61
fix cache line size for Pentium 4
Igor Sysoev <igor@sysoev.ru>
parents:
651
diff
changeset
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96 switch ((cpu[0] & 0xf00) >> 8) { |
611 | 97 |
98 /* Pentium */ | |
99 case 5: | |
1872
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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100 ngx_cacheline_size = 32; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
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changeset
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101 break; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
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102 |
611 | 103 /* Pentium Pro, II, III */ |
104 case 6: | |
105 ngx_cacheline_size = 32; | |
1872
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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106 |
2613
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
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107 model = ((cpu[0] & 0xf0000) >> 8) | (cpu[0] & 0xf0); |
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
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108 |
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
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109 if (model >= 0xd0) { |
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
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110 /* Intel Core, Core 2, Atom */ |
1872
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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111 ngx_cacheline_size = 64; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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112 } |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
|
113 |
611 | 114 break; |
115 | |
116 /* | |
117 * Pentium 4, although its cache line size is 64 bytes, | |
118 * it prefetches up to two cache lines during memory read | |
119 */ | |
120 case 15: | |
121 ngx_cacheline_size = 128; | |
122 break; | |
123 } | |
124 | |
125 } else if (ngx_strcmp(vendor, "AuthenticAMD") == 0) { | |
126 ngx_cacheline_size = 64; | |
127 } | |
128 } | |
129 | |
130 #else | |
131 | |
132 | |
133 void | |
134 ngx_cpuinfo(void) | |
135 { | |
136 } | |
137 | |
138 | |
139 #endif |