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Better with the patch :-) attached to this message
On Sun, 13 Nov 2016 06:03:38 -0800, atoomic@cpan.org wrote:
> This is a bug report for perl from atoomic@cpan.org,
> generated with the help of perlbug 1.40 running under perl 5.25.7.
>
>
> -----------------------------------------------------------------
> [Please describe your issue here]
>
> Increase hash colision ratio and reduce hsplit calls,
> This is a memory (micro) optimization.
>
> Previously the hash array was resized each time the hash contains
> the same number of elements of its size.
>
> With this commit, hash collision is increased to 2*SIZE, which
> has two advantages: resize the hash less often, reduce the size
> of the array for hashes.
>
> As elements are now going to collide a little more, this is
> going to make hash lookup a bit slower.
>
> Note that when resizing the hash we are still using
> 2*Number_of_elements
> (which is 4*Size_of_Hash)
>
> Here are some examples showing the memory optimization resulting from
> this
> change.
> Time is not really relevant here in these samples.
>
> # -------------------------------
> # set of different hash sizes
> # ———————————————
>
> (blead)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my $l1
> (1..10000) { $h{$l1} = {1..$l1} } print qx{grep RSS /proc/$$/status}
> '
> VmRSS: 1480072 kB
>
> real 0m19.072s
> user 0m18.012s
> sys 0m1.060s
>
> (blead+patch)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my
> $l1
> (1..10000) { $h{$l1} = {1..$l1} } print qx{grep RSS /proc/$$/status}
> '
> VmRSS: 1409380 kB (-5%)
>
> real 0m16.707s
> user 0m15.640s
> sys 0m1.068s
>
>
> # -------------------------------
> # large hash grow & read/write access
> # -------------------------------
>
> (blead)> time PERL_HASH_SEED=0 ./perl -e 'my %h; $h{$_} = 1 for
> 1..13107200; $h{$_} = $h{$_ + 1000} for 1..10000; print qx{grep RSS
> /proc/$$/status}'
> VmRSS: 1687840 kB
>
> real 0m20.777s
> user 0m19.548s
> sys 0m1.227s
>
> (blead+patch)> time PERL_HASH_SEED=0 ./perl -e 'my %h; $h{$_} = 1 for
> 1..13107200; $h{$_} = $h{$_ + 1000} for 1..10000; print qx{grep RSS
> /proc/$$/status}'
> VmRSS: 1556784 kB
>
> real 0m20.468s
> user 0m19.412s
> sys 0m1.053s
>
> # -------------------------------
> # 100_000 hashes with 2 keys
> # -------------------------------
>
> (blead)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my $l1
> (1..1000_000) { $h{$l1} = {1..4} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 340300 kB
>
> real 0m2.641s
> user 0m2.370s
> sys 0m0.271s
>
> (blead+patch)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my
> $l1
> (1..100_0000) { $h{$l1} = {1..4} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 332072 kB
>
> real 0m2.647s
> user 0m2.405s
> sys 0m0.242s
>
> # -------------------------------
> # 100_000 hashes with 32 keys
> # -------------------------------
>
> (blead)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my $l1
> (1..100_0000) { $h{$l1} = {1..64} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 2202668 kB
>
> real 0m8.591s
> user 0m7.062s
> sys 0m1.528s
>
> (blead+patch)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my
> $l1
> (1..1000_000) { $h{$l1} = {1..64} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 1942756 kB
>
> real 0m7.755s
> user 0m6.379s
> sys 0m1.377s
>
> # -------------------------------
> # 100_000 hashes with 32 keys
> # -------------------------------
>
> (blead)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my $l1
> (1..10000) { $h{$l1} = {1..1024} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 326848 kB
>
> real 0m1.267s
> user 0m1.006s
> sys 0m0.260s
>
> (blead+patch)> time PERL_HASH_SEED=12345 ./perl -e 'my %h; foreach my
> $l1
> (1..10000) { $h{$l1} = {1..1024} } print qx{grep RSS
> /proc/$$/status} '
> VmRSS: 286512 kB
>
> real 0m1.149s
> user 0m0.919s
> sys 0m0.229s
>
> [Please do not change anything below this line]
> -----------------------------------------------------------------
> ---
> Flags:
> category=core
> severity=low
> Type=Patch
> PatchStatus=HasPatch
> ---
> Site configuration information for perl 5.25.7:
>
> Configured by root at Sun Nov 13 03:43:35 MST 2016.
>
> Summary of my perl5 (revision 5 version 25 subversion 7)
> configuration:
> Commit id: b37d3ac68c2a38a42fd9d7fabe9cf5b8c74d4a83
> Platform:
> osname=linux
> osvers=3.10.0-327.36.3.el7.x86_64
> archname=x86_64-linux
> uname='linux nico-c7.dev.cpanel.net 3.10.0-327.36.3.el7.x86_64 #1
> smp
> mon oct 24 16:09:20 utc 2016 x86_64 x86_64 x86_64 gnulinux '
> config_args='-des -Dusedevel'
> hint=recommended
> useposix=true
> d_sigaction=define
> useithreads=undef
> usemultiplicity=undef
> use64bitint=define
> use64bitall=define
> uselongdouble=undef
> usemymalloc=n
> bincompat5005=undef
> Compiler:
> cc='cc'
> ccflags ='-fwrapv -fno-strict-aliasing -pipe -fstack-protector-
> strong
> -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
> -D_FORTIFY_SOURCE=2'
> optimize='-O2'
> cppflags='-fwrapv -fno-strict-aliasing -pipe -fstack-protector-
> strong
> -I/usr/local/include'
> ccversion=''
> gccversion='4.8.5 20150623 (Red Hat 4.8.5-4)'
> gccosandvers=''
> intsize=4
> longsize=8
> ptrsize=8
> doublesize=8
> byteorder=12345678
> doublekind=3
> d_longlong=define
> longlongsize=8
> d_longdbl=define
> longdblsize=16
> longdblkind=3
> ivtype='long'
> ivsize=8
> nvtype='double'
> nvsize=8
> Off_t='off_t'
> lseeksize=8
> alignbytes=8
> prototype=define
> Linker and Libraries:
> ld='cc'
> ldflags =' -fstack-protector-strong -L/usr/local/lib'
> libpth=/usr/local/lib /usr/lib /lib/../lib64 /usr/lib/../lib64
> /lib
> /lib64 /usr/lib64 /usr/local/lib64
> libs=-lpthread -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc
> -lgdbm_compat
> perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
> libc=libc-2.17.so
> so=so
> useshrplib=false
> libperl=libperl.a
> gnulibc_version='2.17'
> Dynamic Linking:
> dlsrc=dl_dlopen.xs
> dlext=so
> d_dlsymun=undef
> ccdlflags='-Wl,-E'
> cccdlflags='-fPIC'
> lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector-strong'
>
>
> ---
> @INC for perl 5.25.7:
> lib
> /root/.dotfiles/perl-must-have/lib
> /root/perl5/lib/perl5/
> /usr/local/lib/perl5/site_perl/5.25.7/x86_64-linux
> /usr/local/lib/perl5/site_perl/5.25.7
> /usr/local/lib/perl5/5.25.7/x86_64-linux
> /usr/local/lib/perl5/5.25.7
>
> ---
> Environment for perl 5.25.7:
> HOME=/root
> LANG=en_US.UTF-8
> LANGUAGE (unset)
> LD_LIBRARY_PATH (unset)
> LOGDIR (unset)
>
> PATH=/usr/local/cpanel/3rdparty/perl/524/bin:/usr/local/cpanel/3rdparty/perl/522/bin:/usr/local/cpanel/3rdparty/perl/514/bin:/usr/local/cpanel/3rdparty/bin:/root/bin/:/opt/local/bin:/opt/local/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/opt/cpanel/composer/bin:/root/.dotfiles/bin:/root/perl5/bin:/root/.rvm/bin:/root/bin
> PERL5DB=use Devel::NYTProf
> PERL5LIB=/root/.dotfiles/perl-must-
> have/lib::/root/perl5/lib/perl5/
> PERL_BADLANG (unset)
> PERL_CPANM_OPT=--quiet
> SHELL=/bin/bash
---
via perlbug: queue: perl5 status: new
https://rt.perl.org/Ticket/Display.html?id=130084
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