From: Jens Axboe <jens.axboe@oracle.com>
To: petkovbb@gmail.com, bzolnier@gmail.com,
linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/24] ide-tape: remove pipelined mode operation
Date: Sat, 1 Mar 2008 19:36:28 +0100 [thread overview]
Message-ID: <20080301183627.GB6704@kernel.dk> (raw)
In-Reply-To: <20080301154529.GB30547@gollum.tnic>
On Sat, Mar 01 2008, Borislav Petkov wrote:
> On Sat, Mar 01, 2008 at 10:55:18AM +0100, Jens Axboe wrote:
> > On Sat, Mar 01 2008, Borislav Petkov wrote:
> > > Hi Bart,
> > >
> > > here's the 1st draft of the pipeline removal series. As the diffstat below openly
> > > states it, a lot of code got removed - even more than the cleanup series we did
> > > earlier. There are several issues that we need to address concerning these
> > > patches:
> > >
> > > 1. only compile-tested since i don't have the hardware, i.e. longer -mm brewing is
> > > advisable the least.
> > >
> > > 2. I have left the tape->merge_stage buffer structure along with its
> > > alloc/free functions intact for now, for simplicity. The next step would be
> > > to go and carefully audit the code and then remove that last piece
> > > too and use allocations on the stack instead. I guess we still expect
> > > Jens's response on whether blk_{get,put}_request is the way to go here.
> > >
> > > Jens?
> >
> > Hm, I have not seen any questions regarding this directed my way :-)
> > Please point me to the original question and I'll take a look at it.
>
> Hi Jens,
>
> sorry but maybe we weren't that explicit, here's a pointer to the
> relevant thread:
> http://www.mail-archive.com/linux-ide@vger.kernel.org/msg15541.html.
> It boils down to removing the statically allocated arrays of buffers
> for pc and rq structs in ide-floppy and ide-tape, and using GFP_ATOMIC
> stack memory instead. Bart's idea was to even go a step further and
> even avoid allocation errors in out-of-mem situations by reusing
> requests from the request queue but wasn't sure whether this'll fly
> and wanted to run it by you...
That sounds like asking for trouble, if you ask me (well you did :-)
And being a very rarely exercised path (if at all, you should be very
unlucky to NOT get a request even with GFP_ATOMIC), then it wont even
get tested properly. So I'd say stick to GFP_ATOMIC, and just plug the
device and retry if you get into allocation errors.
--
Jens Axboe
next prev parent reply other threads:[~2008-03-01 18:36 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-01 8:58 [PATCH 00/24] ide-tape: remove pipelined mode operation Borislav Petkov
2008-03-01 8:58 ` [PATCH 01/24] ide-tape: remove idetape_pipeline_active() Borislav Petkov
2008-03-02 18:21 ` Bartlomiej Zolnierkiewicz
2008-03-01 8:58 ` [PATCH 02/24] ide-tape: remove pipeline-specific code from idetape_add_chrdev_write_request Borislav Petkov
2008-03-02 18:33 ` Bartlomiej Zolnierkiewicz
2008-03-02 21:19 ` Borislav Petkov
2008-03-02 23:16 ` Bartlomiej Zolnierkiewicz
2008-03-03 6:43 ` Borislav Petkov
2008-03-03 22:32 ` Bartlomiej Zolnierkiewicz
2008-03-01 8:58 ` [PATCH 03/24] ide-tape: remove pipeline-specific code from idetape_add_chrdev_read_request Borislav Petkov
2008-03-02 18:36 ` Bartlomiej Zolnierkiewicz
2008-03-02 21:28 ` Borislav Petkov
2008-03-01 8:58 ` [PATCH 04/24] ide-tape: remove pipeline-specific code from idetape_chrdev_write Borislav Petkov
2008-03-02 18:41 ` Bartlomiej Zolnierkiewicz
2008-03-02 21:31 ` Borislav Petkov
2008-03-02 23:17 ` Bartlomiej Zolnierkiewicz
2008-03-01 8:58 ` [PATCH 05/24] ide-tape: cleanup pipeline-specific code from idetape_init_read Borislav Petkov
2008-03-02 18:48 ` Bartlomiej Zolnierkiewicz
2008-03-01 8:58 ` [PATCH 06/24] ide-tape: remove unused stage-parameter from idetape_copy_stage_to_user Borislav Petkov
2008-03-02 19:15 ` Bartlomiej Zolnierkiewicz
2008-03-01 8:58 ` [PATCH 07/24] ide-tape: remove pipeline-specific code bits from idetape_chrdev_read Borislav Petkov
2008-03-01 8:58 ` [PATCH 08/24] ide-tape: remove pipeline-specific code from idetape_space_over_filemarks Borislav Petkov
2008-03-01 8:58 ` [PATCH 09/24] ide-tape: remove pipeline-specific code from idetape_mtioctop Borislav Petkov
2008-03-01 8:58 ` [RFCPATCH 10/24] ide-tape: remove pipeline-specific code from idetape_chrdev_ioctl Borislav Petkov
2008-03-01 8:58 ` [PATCH 11/24] ide-tape: remove pipeline-specific code from idetape_blkdev_ioctl Borislav Petkov
2008-03-01 8:58 ` [PATCH 12/24] ide-tape: remove idetape_empty_write_pipeline Borislav Petkov
2008-03-01 8:58 ` [PATCH 13/24] ide-tape: remove pipeline-specific code from idetape_chrdev_release Borislav Petkov
2008-03-01 8:58 ` [PATCH 14/24] ide-tape: remove __idetape_discard_read_pipeline Borislav Petkov
2008-03-01 8:58 ` [PATCH 15/24] ide-tape: remove pipeline-specific code from idetape_end_request Borislav Petkov
2008-03-01 8:58 ` [PATCH 16/24] ide-tape: remove idetape_calculate_speeds Borislav Petkov
2008-03-01 8:58 ` [PATCH 17/24] ide-tape: remove pipeline-specific code from idetape_chrdev_open Borislav Petkov
2008-03-01 8:58 ` [PATCH 18/24] ide-tape: remove pipeline-specific code from idetape_setup Borislav Petkov
2008-03-01 8:58 ` [PATCH 19/24] ide-tape: remove pipelined mode parameters Borislav Petkov
2008-03-01 8:58 ` [PATCH 20/24] ide-tape: remove pipelined mode tape control flags Borislav Petkov
2008-03-01 8:58 ` [PATCH 21/24] ide-tape: remove pipeline-specific members from struct ide_tape_obj Borislav Petkov
2008-03-01 8:58 ` [PATCH 22/24] ide-tape: remove misc references to pipelined operation in the comments Borislav Petkov
2008-03-01 8:58 ` [PATCH 23/24] ide-tape: remove pipelined mode description from Documentation/ide/ide-tape.txt Borislav Petkov
2008-03-01 8:58 ` [PATCH 24/24] ide-tape: remove comments markup " Borislav Petkov
2008-03-01 9:55 ` [PATCH 00/24] ide-tape: remove pipelined mode operation Jens Axboe
2008-03-01 15:45 ` Borislav Petkov
2008-03-01 18:36 ` Jens Axboe [this message]
2008-03-01 10:20 ` Adrian Bunk
2008-03-01 15:37 ` Borislav Petkov
2008-03-22 16:09 ` Bartlomiej Zolnierkiewicz
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