Hi, On Tuesday 19 August 2008 18:22:44 Andi Gutmans wrote: > OK checked with Zeev. It seems there are some significant limitations at > least on Windows including that it doesn't work with LoadLibrary() > (which is our bread and butter).
Ok, so there is the same limitations than on Linux with dlopen() :( > There may also be some size limitations on thread local storage. > In any case, this is Windows-only feedback and we may find additional > limitations/compatibility issues on other platforms. > > As there are clear benefits to an increased use of TLS (we already use > it for index caching today) I definitely suggest to revisit this issue > and try and figure out for the variety of platforms whether there's some > middle ground that we can make work. It sounds like a non-trivial > project though. > Arnaud, are you setup to also play around with Windows and possibly some > other OSes to look into this further? Yes, I will try at least with Windows (XP, so no IIS) and FreeBSD. > > Andi > > > > -----Original Message----- > > From: Arnaud Le Blanc [mailto:[EMAIL PROTECTED] > > Sent: Monday, August 18, 2008 10:00 PM > > To: Andi Gutmans > > Cc: PHP Development > > Subject: Re: [PHP-DEV] [PATCH] ZTS as fast as non-ZTS > > > > Hi, > > > > Yes, I have looked for the issue with --with-tsrm-full-__thread-tls > and there > > are effectively some issues. > > > > When building PIC code, the used TLS model is a static model which > does not > > allow modules to be loaded at run-time. glibc's dlopen() sometimes > allow such > > code to be loaded at runtime when it finds some free memory, that's > why -- > > with- > > tsrm-__thread-tls works, but it is not expected to always work. > > > > So when building PIC code that's expected to work only when the > > server/application links the PHP module, or when using LD_PRELOAD, > etc. > > > > Building non-PIC code allows to use a dynamic TLS model, which allows > to load > > modules a run-time, but it is less efficient (4.8s in bench.php, still > faster > > than unpatched version, even non-PIC, but less efficient). > > > > Regards, > > > > Arnaud > > > > On Tuesday 19 August 2008 06:18:51 Andi Gutmans wrote: > > > Hi Arnaud, > > > > > > I remember that at the time we looked at thread local storage and > there > > > were some real issues with it. I can't remember what as it was about > 7+ > > > years ago. > > > I will ask Zeev if he remembers and if not search my archives (don't > > > have years prior to 2007 indexed :'( ). > > > > > > Andi > > > > > > > > > > > > > > > > -----Original Message----- > > > > From: Arnaud Le Blanc [mailto:[EMAIL PROTECTED] > > > > Sent: Saturday, August 16, 2008 7:19 PM > > > > To: PHP Development > > > > Subject: [PHP-DEV] [PATCH] ZTS as fast as non-ZTS > > > > > > > > Hi, > > > > > > > > Currently the way globals work forces to pass a > thread-local-storage > > > pointer > > > > across function calls, which involves some overhead. Also, not all > > > functions > > > > get the pointer as argument and need to use TSRMLS_FETCH(), which > is > > > slow. For > > > > instance emalloc() involves a TSRMLS_FETCH(). An other overhead is > > > accessing > > > > globals, using multiple pointers in different locations. > > > > > > > > The following patch caches each global address in a native TLS > > > variable so > > > > that accessing a global is as simple as global_name->member. This > > > removes the > > > > requirement of passing the tls pointer across function calls, so > that > > > the two > > > > major overheads of ZTS builds are avoided. > > > > > > > > Globals can optionally be declared statically, which speeds up > things > > > a bit. > > > > > > > > Results in bench.php: > > > > non-ZTS: 3.7s > > > > ZTS unpatched: 5.2s > > > > ZTS patched: 4.0s > > > > ZTS patched and static globals: 3.8s > > > > > > > > The patch introduces two new macros: TSRMG_D() (declare) and > > > TSRMG_DH() > > > > (declare, for headers) to declare globals, instead of the current > > > "ts_rsrc_id > > > > foo_global_id". These macros declare the global id, plus the > __thread > > > pointer > > > > to the global storage. > > > > > > > > ts_allocate_id now takes one more callback function as argument to > > > bind the > > > > global pointer to its storage. This callback is declared in > > > TSRMG_D[H](). > > > > > > > > As all TSRMLS_* macros now does nothing, it is needed to call > > > ts_resource(0) > > > > explicitly at least one time in each thread to initialize its > storage. > > > A new > > > > TSRMLS_INIT() macro as been added for this purpose. > > > > > > > > All this is disabled by default. --with-tsrm-__thread-tls enables > the > > > features > > > > of the patch, and --with-tsrm-full-__thread-tls enables static > > > declaration of > > > > globals. > > > > > > > > It as been tested on Linux compiled with --disable-all in CLI and > a > > > bit in > > > > Apache2 with the worker MPM. Known issues: > > > > - Declaring globals statically (--with-tsrm-full-__thread-tls) > causes > > > troubles > > > > to dlopen(), actually Apache wont load the module at runtime (it > works > > > with > > > > just --with-tsrm-__thread-tls). > > > > - The patch assumes that all resources are ts_allocate_id()'ed > before > > > any > > > > other thread calls ts_allocate_id or ts_resource_ex(), which is > > > possibly not > > > > the case. > > > > > > > > The patch needs some tweaks and does not pretend to be included in > any > > > branch, > > > > but I would like to have some comments on it. > > > > > > > > The patch: http://arnaud.lb.s3.amazonaws.com/__thread-tls.patch > > > > > > > > Regards, > > > > > > > > Arnaud > > > > > > > > > > > > -- > > > > PHP Internals - PHP Runtime Development Mailing List > > > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > > Regards, Arnaud -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
