UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

scsi: sd: use mempool for discard special page 

When boxes are run near (or to) OOM, we have a problem with the discard
page allocation in sd. If we fail allocating the special page, we return
busy, and it'll get retried. But since ordering is honored for dispatch
requests, we can keep retrying this same IO and failing. Behind that IO
could be requests that want to free memory, but they never get the
chance. This means you get repeated spews of traces like this:

[1201401.625972] Call Trace:
[1201401.631748]  dump_stack+0x4d/0x65
[1201401.639445]  warn_alloc+0xec/0x190
[1201401.647335]  __alloc_pages_slowpath+0xe84/0xf30
[1201401.657722]  ? get_page_from_freelist+0x11b/0xb10
[1201401.668475]  ? __alloc_pages_slowpath+0x2e/0xf30
[1201401.679054]  __alloc_pages_nodemask+0x1f9/0x210
[1201401.689424]  alloc_pages_current+0x8c/0x110
[1201401.699025]  sd_setup_write_same16_cmnd+0x51/0x150
[1201401.709987]  sd_init_command+0x49c/0xb70
[1201401.719029]  scsi_setup_cmnd+0x9c/0x160
[1201401.727877]  scsi_queue_rq+0x4d9/0x610
[1201401.736535]  blk_mq_dispatch_rq_list+0x19a/0x360
[1201401.747113]  blk_mq_sched_dispatch_requests+0xff/0x190
[1201401.758844]  __blk_mq_run_hw_queue+0x95/0xa0
[1201401.768653]  blk_mq_run_work_fn+0x2c/0x30
[1201401.777886]  process_one_work+0x14b/0x400
[1201401.787119]  worker_thread+0x4b/0x470
[1201401.795586]  kthread+0x110/0x150
[1201401.803089]  ? rescuer_thread+0x320/0x320
[1201401.812322]  ? kthread_park+0x90/0x90
[1201401.820787]  ? do_syscall_64+0x53/0x150
[1201401.829635]  ret_from_fork+0x29/0x40

Ensure that the discard page allocation has a mempool backing, so we
know we can make progress.

Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Jens Axboe 2018-12-12 06:46:55 -07:00 committed by Martin K. Petersen
parent 9e6371d3c6
commit 61cce6f6ee
1 changed files with 19 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/scsi/sd.c
View File

@ -133,6 +133,7 @@ static DEFINE_MUTEX(sd_ref_mutex);
static struct kmem_cache *sd_cdb_cache;
static mempool_t *sd_cdb_pool;
static mempool_t *sd_page_pool;
static const char *sd_cache_types[] = {
"write through", "none", "write back",
@ -759,9 +760,10 @@ static int sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
unsigned int data_len = 24;
char *buf;
rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
rq->special_vec.bv_page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
if (!rq->special_vec.bv_page)
return BLKPREP_DEFER;
clear_highpage(rq->special_vec.bv_page);
rq->special_vec.bv_offset = 0;
rq->special_vec.bv_len = data_len;
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@ -792,9 +794,10 @@ static int sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd, bool unmap)
u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
u32 data_len = sdp->sector_size;
rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
rq->special_vec.bv_page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
if (!rq->special_vec.bv_page)
return BLKPREP_DEFER;
clear_highpage(rq->special_vec.bv_page);
rq->special_vec.bv_offset = 0;
rq->special_vec.bv_len = data_len;
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@ -822,9 +825,10 @@ static int sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd, bool unmap)
u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
u32 data_len = sdp->sector_size;
rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
rq->special_vec.bv_page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
if (!rq->special_vec.bv_page)
return BLKPREP_DEFER;
clear_highpage(rq->special_vec.bv_page);
rq->special_vec.bv_offset = 0;
rq->special_vec.bv_len = data_len;
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@ -1286,7 +1290,7 @@ static void sd_uninit_command(struct scsi_cmnd *SCpnt)
u8 *cmnd;
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
__free_page(rq->special_vec.bv_page);
mempool_free(rq->special_vec.bv_page, sd_page_pool);
if (SCpnt->cmnd != scsi_req(rq)->cmd) {
cmnd = SCpnt->cmnd;
@ -3623,6 +3627,13 @@ static int __init init_sd(void)
goto err_out_cache;
}
sd_page_pool = mempool_create_page_pool(SD_MEMPOOL_SIZE, 0);
if (!sd_page_pool) {
printk(KERN_ERR "sd: can't init discard page pool\n");
err = -ENOMEM;
goto err_out_ppool;
}
err = scsi_register_driver(&sd_template.gendrv);
if (err)
goto err_out_driver;
@ -3630,6 +3641,9 @@ static int __init init_sd(void)
return 0;
err_out_driver:
mempool_destroy(sd_page_pool);
err_out_ppool:
mempool_destroy(sd_cdb_pool);
err_out_cache:
@ -3656,6 +3670,7 @@ static void __exit exit_sd(void)
scsi_unregister_driver(&sd_template.gendrv);
mempool_destroy(sd_cdb_pool);
mempool_destroy(sd_page_pool);
kmem_cache_destroy(sd_cdb_cache);
class_unregister(&sd_disk_class);