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
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# 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"