Date: Tue, 23 Mar 2004 07:40:58 +0300 (MSK) From: Maxim Konovalov <maxim@macomnet.ru> To: John Baldwin <john@baldwin.cx> Cc: Seigo Tanimura <tanimura@tanimura.dyndns.org> Subject: Re: Is MTX_CONTESTED evil? Message-ID: <20040323073742.C62061@mp3files.int.ru> In-Reply-To: <200403221906.47238.john@baldwin.cx> References: <200403160519.i2G5J0V6023193@urban> <200403220657.i2M6vCrS097750@shojaku.t.axe-inc.co.jp> <200403221906.47238.john@baldwin.cx>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 22 Mar 2004, 19:06-0500, John Baldwin wrote: [...] > > By the way, one thing to keep in mind is that Solaris has working > > adaptive mutexes. For adaptive mutexes, the waiting case is > > almost never supposed to happen, so it's more reasonable for them > > to wake all waiters. However, AFAIK, FreeBSD's adaptive mutex > > support is incomplete or broken at this point, so you may run into > > a thundering herd problem if you wake all waiters. > > Adaptive mutexes work just fine, but they aren't on by default. In FreeBSD, > adaptive mutexes spin so long as the owner is still executing on another CPU. With 'options ADATIVE_MUTEXES' our SMP testbox crashes very reliable. If you are interested in a traceback and/or crashdump let me know. -- Maxim Konovalov
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040323073742.C62061>