From owner-kaio@oss.sgi.com Sun Mar 18 15:57:43 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2INvhb19685 for kaio-outgoing; Sun, 18 Mar 2001 15:57:43 -0800 Received: from horus.its.uow.edu.au (horus.its.uow.edu.au [130.130.68.25]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2INvfM19682 for ; Sun, 18 Mar 2001 15:57:41 -0800 Received: from uow.edu.au (wumpus.its.uow.edu.au [130.130.68.12]) by horus.its.uow.edu.au (8.9.3/8.9.3) with ESMTP id KAA08119 for ; Mon, 19 Mar 2001 10:57:39 +1100 (EST) Message-ID: <3AB54B71.80DB2CC9@uow.edu.au> Date: Sun, 18 Mar 2001 23:57:37 +0000 From: Andrew Morton X-Mailer: Mozilla 4.61 [en] (X11; I; Linux 2.4.2-ac19 i686) X-Accept-Language: en MIME-Version: 1.0 To: kaio@oss.sgi.com Subject: spotted in the kaio patch Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-kaio@oss.sgi.com Precedence: bulk I was surfing this patch... do_kaio_generic_read() does a page_cache_alloc() with the pagecache_lock held - can deadlock. In kaio_set_slave_name(), do this: current->mm->arg_start = current->mm->arg_end = 0; and the slaves will look right in `ps'. From owner-kaio@oss.sgi.com Mon Mar 19 10:25:50 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2JIPoM05954 for kaio-outgoing; Mon, 19 Mar 2001 10:25:50 -0800 Received: from pneumatic-tube.sgi.com (pneumatic-tube.sgi.com [204.94.214.22]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2JIPoM05951 for ; Mon, 19 Mar 2001 10:25:50 -0800 Received: from madurai.engr.sgi.com (madurai.engr.sgi.com [163.154.5.75]) by pneumatic-tube.sgi.com (980327.SGI.8.8.8-aspam/980310.SGI-aspam) via ESMTP id KAA07893 for ; Mon, 19 Mar 2001 10:35:47 -0800 (PST) mail_from (ananth@sgi.com) Received: from sgi.com (mango.engr.sgi.com [163.154.5.76]) by madurai.engr.sgi.com (980427.SGI.8.8.8/970903.SGI.AUTOCF) via ESMTP id KAA24013; Mon, 19 Mar 2001 10:20:07 -0800 (PST) Message-ID: <3AB64E89.7374E767@sgi.com> Date: Mon, 19 Mar 2001 10:23:05 -0800 From: Rajagopal Ananthanarayanan X-Mailer: Mozilla 4.72 [en] (X11; U; Linux 2.2.16-4SGI_20smp i686) X-Accept-Language: en MIME-Version: 1.0 To: Andrew Morton CC: kaio@oss.sgi.com Subject: Re: spotted in the kaio patch References: <3AB54B71.80DB2CC9@uow.edu.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-kaio@oss.sgi.com Precedence: bulk Andrew Morton wrote: > > I was surfing this patch... > > do_kaio_generic_read() does a page_cache_alloc() with the > pagecache_lock held - can deadlock. I'll look into this ... > > In kaio_set_slave_name(), do this: > > current->mm->arg_start = current->mm->arg_end = 0; > > and the slaves will look right in `ps'. Ah, so that's the trick, thanks. I had always wanted to fix this, but never got around to it. Interestingly top reports the correct names even without this fix. Just curious: did you find these bugs by running the patch or by code examination? cheers, ananth. -- -------------------------------------------------------------------------- Rajagopal Ananthanarayanan ("ananth") Member Technical Staff, SGI. -------------------------------------------------------------------------- From owner-kaio@oss.sgi.com Mon Mar 19 12:09:47 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2JK9lG07919 for kaio-outgoing; Mon, 19 Mar 2001 12:09:47 -0800 Received: from sgi.com (sgi.SGI.COM [192.48.153.1]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2JK9kM07912 for ; Mon, 19 Mar 2001 12:09:46 -0800 Received: from madurai.engr.sgi.com ([163.154.5.75]) by sgi.com (980327.SGI.8.8.8-aspam/980304.SGI-aspam: SGI does not authorize the use of its proprietary systems or networks for unsolicited or bulk email from the Internet.) via ESMTP id MAA05513 for ; Mon, 19 Mar 2001 12:09:37 -0800 (PST) mail_from (ananth@sgi.com) Received: from sgi.com (mango.engr.sgi.com [163.154.5.76]) by madurai.engr.sgi.com (980427.SGI.8.8.8/970903.SGI.AUTOCF) via ESMTP id MAA24106; Mon, 19 Mar 2001 12:02:59 -0800 (PST) Message-ID: <3AB666A5.AE26B121@sgi.com> Date: Mon, 19 Mar 2001 12:05:57 -0800 From: Rajagopal Ananthanarayanan X-Mailer: Mozilla 4.72 [en] (X11; U; Linux 2.2.16-4SGI_20smp i686) X-Accept-Language: en MIME-Version: 1.0 To: kaio@oss.sgi.com Subject: KAIO 1.3.1 for Linux 2.4.2 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-kaio@oss.sgi.com Precedence: bulk Roll-up to the next current Linux 2.4.2 release and incorporate bug fixes from Andrew Morton. Current KAIO version is 1.3.1. Checkout: http://oss.sgi.com/projects/kaio/download -- -------------------------------------------------------------------------- Rajagopal Ananthanarayanan ("ananth") Member Technical Staff, SGI. -------------------------------------------------------------------------- From owner-kaio@oss.sgi.com Mon Mar 19 14:39:37 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2JMdbv11437 for kaio-outgoing; Mon, 19 Mar 2001 14:39:37 -0800 Received: from horus.its.uow.edu.au (horus.its.uow.edu.au [130.130.68.25]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2JMdYM11434 for ; Mon, 19 Mar 2001 14:39:35 -0800 Received: from uow.edu.au (wumpus.its.uow.edu.au [130.130.68.12]) by horus.its.uow.edu.au (8.9.3/8.9.3) with ESMTP id JAA22759; Tue, 20 Mar 2001 09:39:26 +1100 (EST) Message-ID: <3AB68A9D.346346FC@uow.edu.au> Date: Mon, 19 Mar 2001 22:39:25 +0000 From: Andrew Morton X-Mailer: Mozilla 4.61 [en] (X11; I; Linux 2.4.2-ac19 i686) X-Accept-Language: en MIME-Version: 1.0 To: Rajagopal Ananthanarayanan CC: kaio@oss.sgi.com Subject: Re: spotted in the kaio patch References: <3AB54B71.80DB2CC9@uow.edu.au> <3AB64E89.7374E767@sgi.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-kaio@oss.sgi.com Precedence: bulk Rajagopal Ananthanarayanan wrote: > > ... > > > > > In kaio_set_slave_name(), do this: > > > > current->mm->arg_start = current->mm->arg_end = 0; > > > > and the slaves will look right in `ps'. > > Ah, so that's the trick, thanks. I had always wanted to fix this, > but never got around to it. Interestingly top reports the correct > names even without this fix. mm.. I assume `ps' sees an empty argv and then falls back to tsk->comm and puts "[]" around it. It seems that `top' uses ->comm[] all the time, unless you give it the 'c' option. > Just curious: did you find these bugs by running the patch or > by code examination? >From reading the code. It's *very* readable code. Thank you! It makes me want to read the raw I/O patch :) Question, please: - I note that Ben LaHaise's embryonic aio patch saves a copy_from_user by pinning the user pages down (map_user_kiobuf). I assume they're marked COW while I/O is in progress. Have you considered doing this? Do you expect there would be benefit (despite Linus' predictions)? Thanks. From owner-kaio@oss.sgi.com Mon Mar 19 15:44:22 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2JNiMW12784 for kaio-outgoing; Mon, 19 Mar 2001 15:44:22 -0800 Received: from pneumatic-tube.sgi.com (pneumatic-tube.sgi.com [204.94.214.22]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2JNiLM12781 for ; Mon, 19 Mar 2001 15:44:21 -0800 Received: from madurai.engr.sgi.com (madurai.engr.sgi.com [163.154.5.75]) by pneumatic-tube.sgi.com (980327.SGI.8.8.8-aspam/980310.SGI-aspam) via ESMTP id PAA07087 for ; Mon, 19 Mar 2001 15:54:18 -0800 (PST) mail_from (ananth@sgi.com) Received: from sgi.com (mango.engr.sgi.com [163.154.5.76]) by madurai.engr.sgi.com (980427.SGI.8.8.8/970903.SGI.AUTOCF) via ESMTP id PAA24547; Mon, 19 Mar 2001 15:38:12 -0800 (PST) Message-ID: <3AB69916.B71EF26E@sgi.com> Date: Mon, 19 Mar 2001 15:41:10 -0800 From: Rajagopal Ananthanarayanan X-Mailer: Mozilla 4.72 [en] (X11; U; Linux 2.2.16-4SGI_20smp i686) X-Accept-Language: en MIME-Version: 1.0 To: Andrew Morton CC: kaio@oss.sgi.com, mingo@elte.hu Subject: Re: spotted in the kaio patch References: <3AB54B71.80DB2CC9@uow.edu.au> <3AB64E89.7374E767@sgi.com> <3AB68A9D.346346FC@uow.edu.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-kaio@oss.sgi.com Precedence: bulk Andrew Morton wrote: > > >From reading the code. It's *very* readable code. Thank you! > It makes me want to read the raw I/O patch :) Thank you for finding bugs in it ;-) > > Question, please: > > - I note that Ben LaHaise's embryonic aio patch > saves a copy_from_user by pinning the user pages down > (map_user_kiobuf). I assume they're marked COW while I/O > is in progress. Have you considered doing this? Do > you expect there would be benefit (despite Linus' > predictions)? Well, not really. kiobufs are limited to "normal" file I/O. People who care about copying will use O_DIRECT or avoid it completely by using RAW devices ... most databases which are one important classs of AIO users have optimizations for both RAW & DIRECT. The one aspect of kiobuf's I like is that they provide a simple means of "pinning" memory belonging to a user address space. And I like that not because that enables less copying, but because the container can be handed over to another thread/process. In the end I would like KAIO to use system-wide threads for handling AIO events (such as completion of IO) ... Ben's patch uses keventd, so that is one approach. However, Ingo Molnar had suggested not using any threads at all, but I don't know how that would work. I'm cc:'ing Ingo just in case he has better ideas. -------------------------------------------------------------------------- Rajagopal Ananthanarayanan ("ananth") Member Technical Staff, SGI. -------------------------------------------------------------------------- From owner-kaio@oss.sgi.com Mon Mar 26 04:01:53 2001 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2QC1rX18613 for kaio-outgoing; Mon, 26 Mar 2001 04:01:53 -0800 Received: from giasmd01.vsnl.net.in (giasmd01.vsnl.net.in [202.54.6.1]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2QC1qM18596 for ; Mon, 26 Mar 2001 04:01:52 -0800 Received: from hotpop.com (unknown [203.197.130.99]) by giasmd01.vsnl.net.in (Postfix) with SMTP id 5E82EE544 for ; Mon, 26 Mar 2001 17:41:46 +0530 (IST) From: "Murali Kumar" To: Subject: New LINUX Web Site Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Date: Mon, 26 Mar 2001 17:35:22 +0530 Content-Transfer-Encoding: 8bit Message-Id: <20010326121146.5E82EE544@giasmd01.vsnl.net.in> Sender: owner-kaio@oss.sgi.com Precedence: bulk Dear Sir, We have launched Linux Section http://www.softlandindia.com/Linux/ on March 12, 2001. India's Website for Linux OS, Freeware and Shareware Downloads. All the Best Softwares are listed and organized in Categories with the latest versions. New Softwares are Added Every Day. Please Visit us. http://www.softlandindia.com/Linux/ Software Submit Format can be had from http://www.softlandindia.com/Linux/Submit.htm Sincerely yours, K.Murali Kumar Webmaster www.softlandindia.com Email Ids: linux.softlandindia@hotpop.com and linuxsoftlandindia@hotpop.com