Mercurial > hg > nginx-quic
view auto/cc/icc @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | 9eefb38f0005 |
children |
line wrap: on
line source
# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. # Intel C++ compiler 7.1, 8.0, 8.1, 9.0, 11.1 NGX_ICC_VER=`$CC -V 2>&1 | grep 'Version' 2>&1 \ | sed -e 's/^.* Version \([^ ]*\) *Build.*$/\1/'` echo " + icc version: $NGX_ICC_VER" have=NGX_COMPILER value="\"Intel C Compiler $NGX_ICC_VER\"" . auto/define # optimizations CFLAGS="$CFLAGS -O" CORE_LINK="$CORE_LINK -opt_report_file=$NGX_OBJS/opt_report_file" case $CPU in pentium) # optimize for Pentium and Athlon CPU_OPT="-march=pentium" ;; pentiumpro) # optimize for Pentium Pro, Pentium II and Pentium III CPU_OPT="-mcpu=pentiumpro -march=pentiumpro" ;; pentium4) # optimize for Pentium 4, default CPU_OPT="-march=pentium4" ;; esac CFLAGS="$CFLAGS $CPU_OPT" if [ ".$PCRE_OPT" = "." ]; then PCRE_OPT="-O $CPU_OPT" fi if [ ".$ZLIB_OPT" = "." ]; then ZLIB_OPT="-O $CPU_OPT" fi # warnings CFLAGS="$CFLAGS -w2" # disable some warnings # invalid type conversion: "int" to "char *" CFLAGS="$CFLAGS -wd171" # argument is incompatible with corresponding format string conversion CFLAGS="$CFLAGS -wd181" # zero used for undefined preprocessing identifier CFLAGS="$CFLAGS -wd193" # the format string ends before this argument CFLAGS="$CFLAGS -wd268" # invalid format string conversion CFLAGS="$CFLAGS -wd269" # conversion from "long long" to "size_t" may lose significant bits CFLAGS="$CFLAGS -wd810" # parameter was never referenced CFLAGS="$CFLAGS -wd869" # attribute "unused" is only allowed in a function definition, warning on pTHX_ CFLAGS="$CFLAGS -wd1301" # STUB # enumerated type mixed with another type CFLAGS="$CFLAGS -wd188" # controlling expression is constant CFLAGS="$CFLAGS -wd279" # operands are evaluated in unspecified order CFLAGS="$CFLAGS -wd981" # external definition with no prior declaration CFLAGS="$CFLAGS -wd1418" # external declaration in primary source file CFLAGS="$CFLAGS -wd1419" case "$NGX_ICC_VER" in 9.*) # "cc" clobber ignored, warnings for Linux's htonl()/htons() CFLAGS="$CFLAGS -wd1469" # explicit conversion of a 64-bit integral type to a smaller # integral type CFLAGS="$CFLAGS -wd1683" # conversion from pointer to same-sized integral type, # warning on offsetof() CFLAGS="$CFLAGS -wd1684" # floating-point equality and inequality comparisons are unreliable, # warning on SvTRUE() CFLAGS="$CFLAGS -wd1572" ;; 8.*) # "cc" clobber ignored, warnings for Linux's htonl()/htons() CFLAGS="$CFLAGS -wd1469" # floating-point equality and inequality comparisons are unreliable, # warning on SvTRUE() CFLAGS="$CFLAGS -wd1572" ;; *) ;; esac # stop on warning CFLAGS="$CFLAGS -Werror" # debug CFLAGS="$CFLAGS -g"