On 25 March 2014 15:11, Bert Huijben <b...@qqmail.nl> wrote: > > >> -----Original Message----- >> From: Ivan Zhakov [mailto:i...@visualsvn.com] >> Sent: dinsdag 25 maart 2014 12:03 >> To: Subversion Development; Bert Huijben >> Subject: Re: svn commit: r1344347 - >> /subversion/trunk/subversion/libsvn_subr/config_file.c >> >> On 30 May 2012 20:52, <rhuij...@apache.org> wrote: >> > Author: rhuijben >> > Date: Wed May 30 16:52:36 2012 >> > New Revision: 1344347 >> > >> > URL: http://svn.apache.org/viewvc?rev=1344347&view=rev >> > Log: >> > Remove about 15% of the cpu overhead of svnserve and httpd while >> running the >> > test suite by introducing a very simple parser buffer in the config file >> > parser >> > code. >> > >> > The nice clean stream translation code had an 7 times overhead on this >> very >> > performance critical code path, while clients of svnserve and httpd were >> > waiting. (Before this patch the this code path used 22% of the cpu time, >> > now just 3%) >> > >> > * subversion/libsvn_subr/config_file.c >> > (parse_context_t): Add buffer and position variables. Use EOF as no >> ungetc var. >> > (parser_getc): Skip '\r' characters as we only need the '\n' character >> > for >> our >> > config files. Use EOF as no ungetc var. >> > (parse_option, >> > parse_section_name): Rename pool argument to scratch_pool. >> > (svn_config__parse_file): Create scratch pool and store the file and >> > parse >> > ctx in it. Update initialization and destroy scratch_pool after >> > successfull >> > parsing. >> > >> > Modified: >> > subversion/trunk/subversion/libsvn_subr/config_file.c >> > >> > Modified: subversion/trunk/subversion/libsvn_subr/config_file.c >> > URL: >> http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/co >> nfig_file.c?rev=1344347&r1=1344346&r2=1344347&view=diff >> > >> ========================================================== >> ==================== >> > --- subversion/trunk/subversion/libsvn_subr/config_file.c (original) >> > +++ subversion/trunk/subversion/libsvn_subr/config_file.c Wed May 30 >> 16:52:36 2012 >> > @@ -60,15 +60,19 @@ typedef struct parse_context_t >> > /* The current line in the file */ >> > int line; >> > >> > - /* Cached ungotten character - streams don't support ungetc() >> > - [emulate it] */ >> > + /* Emulate an ungetc */ >> > int ungotten_char; >> > - svn_boolean_t have_ungotten_char; >> > >> > - /* Temporary strings, allocated from the temp pool */ >> > + /* Temporary strings */ >> > svn_stringbuf_t *section; >> > svn_stringbuf_t *option; >> > svn_stringbuf_t *value; >> > + >> > + /* Parser buffer for getc() to avoid call overhead into several >> > libraries >> > + for every character */ >> > + char parser_buffer[SVN_STREAM_CHUNK_SIZE]; /* Larger than most >> config files */ >> Hi Bert, >> >> Did you have specific reasons for using deprecated >> SVN_STREAM_CHUNK_SIZE (100 kb) instead of SVN__STREAM_CHUNK_SIZE >> (16kb) constant for read buffer? I'm asking because it seems this >> significantly increase memory footprint for high loaded servers due >> APR allocator behavior and fragmentation. >> >> I would like change this buffer to 16kb instead of 100kb, if you don't >> have strong objections. > > Answered on IRC: +1 > > Using something like <= 8 KByte would not handle our default generated client > side config files... > But 16 KB will easily hold them. > > The fsfs and repository config files are much smaller, so if it really helps > we could make this configurable per use case. > Bert,
Thanks for quick reply. Committed in r1581296 and nominated for backport to 1.8.x. -- Ivan Zhakov CTO | VisualSVN | http://www.visualsvn.com
