From: Dave Olien <dmo@osdl.org>
To: Nick Piggin <piggin@cyberone.com.au>
Cc: Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, axboe@suse.de
Subject: Re: Badness in as_completed_request warning
Date: Tue, 9 Sep 2003 08:38:16 -0700 [thread overview]
Message-ID: <20030909153816.GA16855@osdl.org> (raw)
In-Reply-To: <3F5D7B6A.70703@cyberone.com.au>
[-- Attachment #1: Type: text/plain, Size: 4122 bytes --]
Sorry, this one Bug()'d really quickly. I applied this patch to
an unmodified test5 kernel. Console output is attached.
On Tue, Sep 09, 2003 at 05:04:10PM +1000, Nick Piggin wrote:
>
> Thanks Dave,
> Can you try this one? I can't reproduce the problem here as I don't have
> enough disks unfortunately. Thanks
>
> Nick
> linux-2.6-npiggin/drivers/block/as-iosched.c | 60 +++++++++++++++++++--------
> 1 files changed, 43 insertions(+), 17 deletions(-)
>
> diff -puN drivers/block/as-iosched.c~as-warn-fix drivers/block/as-iosched.c
> --- linux-2.6/drivers/block/as-iosched.c~as-warn-fix 2003-09-09 17:02:41.000000000 +1000
> +++ linux-2.6-npiggin/drivers/block/as-iosched.c 2003-09-09 17:02:41.000000000 +1000
> @@ -373,7 +373,7 @@ static void as_move_to_dispatch(struct a
> * direct IO, then move the alias to the dispatch list and then add the
> * request.
> */
> -static void as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
> +static int as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
> {
> struct as_rq *alias;
> struct request *rq = arq->request;
> @@ -381,10 +381,20 @@ static void as_add_arq_rb(struct as_data
> arq->rb_key = rq_rb_key(rq);
>
> /* This can be caused by direct IO */
> +#if 0
> while ((alias = __as_add_arq_rb(ad, arq)))
> as_move_to_dispatch(ad, alias);
> +#endif
> + if ((alias = __as_add_arq_rb(ad, arq))) {
> + arq->state = AS_RQ_NEW;
> + list_add_tail(&arq->request->queuelist,
> + &alias->request->queuelist);
> +
> + return 1;
> + }
>
> rb_insert_color(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
> + return 0;
> }
>
> static inline void as_del_arq_rb(struct as_data *ad, struct as_rq *arq)
> @@ -1131,7 +1141,21 @@ static void as_move_to_dispatch(struct a
> * take it off the sort and fifo list, add to dispatch queue
> */
> as_remove_queued_request(ad->q, arq->request);
> +
> + for (;;) {
> + struct list_head *alias = &arq->request->queuelist;
> +
> + if (!list_empty(alias)) {
> + struct request *rq;
> + rq = list_entry_rq(alias->next);
> + list_del(&rq->queuelist);
> + list_add_tail(&rq->queuelist, ad->dispatch);
> + } else
> + break;
> + }
> +
> list_add_tail(&arq->request->queuelist, ad->dispatch);
> +
> if (arq->io_context && arq->io_context->aic)
> atomic_inc(&arq->io_context->aic->nr_dispatched);
>
> @@ -1303,22 +1327,22 @@ static void as_add_request(struct as_dat
> arq->is_sync = 0;
> data_dir = arq->is_sync;
>
> - arq->io_context = as_get_io_context();
> + if (!as_add_arq_rb(ad, arq)) {
> + arq->io_context = as_get_io_context();
>
> - if (arq->io_context) {
> - atomic_inc(&arq->io_context->aic->nr_queued);
> - as_update_iohist(arq->io_context->aic, arq->request);
> - }
> -
> - as_add_arq_rb(ad, arq);
> + if (arq->io_context) {
> + atomic_inc(&arq->io_context->aic->nr_queued);
> + as_update_iohist(arq->io_context->aic, arq->request);
> + }
>
> - /*
> - * set expire time (only used for reads) and add to fifo list
> - */
> - arq->expires = jiffies + ad->fifo_expire[data_dir];
> - list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
> - arq->state = AS_RQ_QUEUED;
> - as_update_arq(ad, arq); /* keep state machine up to date */
> + /*
> + * set expire time (only used for reads) and add to fifo list
> + */
> + arq->expires = jiffies + ad->fifo_expire[data_dir];
> + list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
> + arq->state = AS_RQ_QUEUED;
> + as_update_arq(ad, arq); /* keep state machine up to date */
> + }
> }
>
> /*
> @@ -1495,7 +1519,8 @@ static void as_merged_request(request_qu
> */
> if (rq_rb_key(req) != arq->rb_key) {
> as_del_arq_rb(ad, arq);
> - as_add_arq_rb(ad, arq);
> + if (as_add_arq_rb(ad, arq))
> + WARN_ON(1);
> /*
> * Note! At this stage of this and the next function, our next
> * request may not be optimal - eg the request may have "grown"
> @@ -1526,7 +1551,8 @@ as_merged_requests(request_queue_t *q, s
>
> if (rq_rb_key(req) != arq->rb_key) {
> as_del_arq_rb(ad, arq);
> - as_add_arq_rb(ad, arq);
> + if (as_add_arq_rb(ad, arq))
> + WARN_ON(1);
> }
>
> /*
>
> _
[-- Attachment #2: typescript --]
[-- Type: text/plain, Size: 2147 bytes --]
root@cl045 root]# ------------[ cut here ]------------
kernel BUG at drivers/block/as-iosched.c:302!
invalid operand: 0000 [#1]
CPU: 0
EIP: 0060:[<c021a880>] Not tainted
EFLAGS: 00010046
EIP is at as_find_arq_hash+0x80/0x90
eax: 00000000 ebx: d2fc8ed4 ecx: d2fc8ed4 edx: d2fc8eb8
esi: d2fc9ec0 edi: c17319e0 ebp: 007c054f esp: dd4fdae0
ds: 007b es: 007b ss: 0068
Process mkfs.ext2 (pid: 1276, threadinfo=dd4fc000 task=df5b06f0)
Stack: c4acd320 c1731a00 007c0551 00000000 c021bf54 dfd3cbc0 007c054f d41d6a98
c0215a49 dfd3cbc0 00000000 c1731a00 d41d6a98 00000001 c0213709 c1731a00
dd4fdb4c c4acd320 c0216578 c1731a00 dd4fdb4c c4acd320 00000000 007c054f
Call Trace:
[<c021bf54>] as_merge+0xe4/0x170
[<c0215a49>] get_request+0x1b9/0x2a0
[<c0213709>] elv_merge+0x29/0x30
[<c0216578>] __make_request+0x338/0x580
[<c02168d5>] generic_make_request+0x115/0x1a0
[<c0119ebd>] smp_apic_timer_interrupt+0xdd/0x150
[<c015d917>] bio_alloc+0xd7/0x1c0
[<c02169b4>] submit_bio+0x54/0xa0
[<c015b660>] __block_write_full_page+0x270/0x470
[<c015ceda>] block_write_full_page+0xfa/0x120
[<c015fcc0>] blkdev_get_block+0x0/0x60
[<c015fe3f>] blkdev_writepage+0x1f/0x30
[<c015fcc0>] blkdev_get_block+0x0/0x60
[<c017a308>] mpage_writepages+0x208/0x2db
[<c015fe20>] blkdev_writepage+0x0/0x30
[<c016102f>] generic_writepages+0x1f/0x23
[<c014198e>] do_writepages+0x1e/0x40
[<c0178866>] __sync_single_inode+0xc6/0x220
[<c0178c1c>] sync_sb_inodes+0x1ac/0x270
[<c0178d4a>] writeback_inodes+0x6a/0xa0
[<c0141438>] balance_dirty_pages+0xb8/0x160
[<c013e1ad>] generic_file_aio_write_nolock+0x4cd/0xac0
[<c013cbf1>] file_read_actor+0xe1/0x100
[<c010b96e>] apic_timer_interrupt+0x1a/0x20
[<c013e81e>] generic_file_write_nolock+0x7e/0xa0
[<c011e8e0>] default_wake_function+0x0/0x30
[<c012a906>] update_wall_time+0x16/0x40
[<c012ad30>] do_timer+0xc0/0xd0
[<c0111826>] timer_interrupt+0x56/0x110
[<c0160dd7>] blkdev_file_write+0x37/0x40
[<c015844e>] vfs_write+0xbe/0x130
[<c0158572>] sys_write+0x42/0x70
[<c010af2d>] sysenter_past_esp+0x52/0x71
Code: 0f 0b 2e 01 49 bf 30 c0 eb b5 8d b6 00 00 00 00 8b 54 24 08
next prev parent reply other threads:[~2003-09-09 15:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-08 16:48 Badness in as_completed_request warning Dave Olien
2003-09-09 3:40 ` Nick Piggin
2003-09-09 6:12 ` Dave Olien
2003-09-09 7:04 ` Nick Piggin
2003-09-09 15:38 ` Dave Olien [this message]
2003-09-09 16:44 ` Dave Olien
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20030909153816.GA16855@osdl.org \
--to=dmo@osdl.org \
--cc=akpm@osdl.org \
--cc=axboe@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=piggin@cyberone.com.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.