Mercurial > hg > nginx-quic
annotate src/core/ngx_cpuinfo.c @ 4207:4fc91bae6f83
Better recheck of dead upstream servers.
Previously nginx used to mark backend again as live as soon as fail_timeout
passes (10s by default) since last failure. On the other hand, detecting
dead backend takes up to 60s (proxy_connect_timeout) in typical situation
"backend is down and doesn't respond to any packets". This resulted in
suboptimal behaviour in the above situation (up to 23% of requests were
directed to dead backend with default settings).
More detailed description of the problem may be found here (in Russian):
http://mailman.nginx.org/pipermail/nginx-ru/2011-August/042172.html
Fix is to only allow one request after fail_timeout passes, and
mark backend as "live" only if this request succeeds.
Note that with new code backend will not be marked "live" unless "check"
request is completed, and this may take a while in some specific workloads
(e.g. streaming). This is believed to be acceptable.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 12 Oct 2011 14:22:48 +0000 |
parents | b863be280d3b |
children | d620f497c50f |
rev | line source |
---|---|
611 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4 */ | |
5 | |
6 | |
7 #include <ngx_config.h> | |
8 #include <ngx_core.h> | |
9 | |
10 | |
11 #if (( __i386__ || __amd64__ ) && ( __GNUC__ || __INTEL_COMPILER )) | |
12 | |
13 | |
14 static ngx_inline void ngx_cpuid(uint32_t i, uint32_t *buf); | |
15 | |
16 | |
617 | 17 #if ( __i386__ ) |
18 | |
19 static ngx_inline void | |
20 ngx_cpuid(uint32_t i, uint32_t *buf) | |
21 { | |
22 | |
23 /* | |
24 * we could not use %ebx as output parameter if gcc builds PIC, | |
25 * and we could not save %ebx on stack, because %esp is used, | |
26 * when the -fomit-frame-pointer optimization is specified. | |
27 */ | |
28 | |
29 __asm__ ( | |
30 | |
31 " mov %%ebx, %%esi; " | |
32 | |
33 " cpuid; " | |
651 | 34 " mov %%eax, (%1); " |
35 " mov %%ebx, 4(%1); " | |
36 " mov %%edx, 8(%1); " | |
37 " mov %%ecx, 12(%1); " | |
617 | 38 |
39 " mov %%esi, %%ebx; " | |
40 | |
651 | 41 : : "a" (i), "D" (buf) : "ecx", "edx", "esi", "memory" ); |
617 | 42 } |
43 | |
44 | |
45 #else /* __amd64__ */ | |
46 | |
47 | |
611 | 48 static ngx_inline void |
49 ngx_cpuid(uint32_t i, uint32_t *buf) | |
50 { | |
51 uint32_t eax, ebx, ecx, edx; | |
52 | |
53 __asm__ ( | |
54 | |
55 "cpuid" | |
56 | |
57 : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (i) ); | |
58 | |
59 buf[0] = eax; | |
60 buf[1] = ebx; | |
61 buf[2] = edx; | |
62 buf[3] = ecx; | |
63 } | |
64 | |
65 | |
617 | 66 #endif |
67 | |
68 | |
611 | 69 /* auto detect the L2 cache line size of modern and widespread CPUs */ |
70 | |
71 void | |
72 ngx_cpuinfo(void) | |
73 { | |
74 u_char *vendor; | |
2613
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
|
75 uint32_t vbuf[5], cpu[4], model; |
611 | 76 |
77 vbuf[0] = 0; | |
78 vbuf[1] = 0; | |
79 vbuf[2] = 0; | |
80 vbuf[3] = 0; | |
81 vbuf[4] = 0; | |
82 | |
83 ngx_cpuid(0, vbuf); | |
84 | |
85 vendor = (u_char *) &vbuf[1]; | |
86 | |
87 if (vbuf[0] == 0) { | |
88 return; | |
89 } | |
90 | |
91 ngx_cpuid(1, cpu); | |
92 | |
93 if (ngx_strcmp(vendor, "GenuineIntel") == 0) { | |
94 | |
1871
9afb84c7cc61
fix cache line size for Pentium 4
Igor Sysoev <igor@sysoev.ru>
parents:
651
diff
changeset
|
95 switch ((cpu[0] & 0xf00) >> 8) { |
611 | 96 |
97 /* Pentium */ | |
98 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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99 ngx_cacheline_size = 32; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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100 break; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
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101 |
611 | 102 /* Pentium Pro, II, III */ |
103 case 6: | |
104 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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105 |
2613
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
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106 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
|
107 |
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
|
108 if (model >= 0xd0) { |
b863be280d3b
update cpuid for Core 2 and Atom
Igor Sysoev <igor@sysoev.ru>
parents:
1872
diff
changeset
|
109 /* Intel Core, Core 2, Atom */ |
1872
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
|
110 ngx_cacheline_size = 64; |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
|
111 } |
8e88522cb6da
detect L2 cache line size for Intel Core
Igor Sysoev <igor@sysoev.ru>
parents:
1871
diff
changeset
|
112 |
611 | 113 break; |
114 | |
115 /* | |
116 * Pentium 4, although its cache line size is 64 bytes, | |
117 * it prefetches up to two cache lines during memory read | |
118 */ | |
119 case 15: | |
120 ngx_cacheline_size = 128; | |
121 break; | |
122 } | |
123 | |
124 } else if (ngx_strcmp(vendor, "AuthenticAMD") == 0) { | |
125 ngx_cacheline_size = 64; | |
126 } | |
127 } | |
128 | |
129 #else | |
130 | |
131 | |
132 void | |
133 ngx_cpuinfo(void) | |
134 { | |
135 } | |
136 | |
137 | |
138 #endif |