Revision c4f675cd40d955d539180506c09515c90169b15b authored by Sergei Trofimovich on 20 May 2011, 20:20:30 UTC, committed by Chris Mason on 23 May 2011, 17:24:14 UTC
Observed as a large delay when --mixed filesystem is filled up. Test example: 1. create tiny --mixed FS: $ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1 $ mkfs.btrfs --mixed 2G.img $ mount -oloop 2G.img /mnt/ut/ 2. Try to fill it up: $ dd if=/dev/urandom of=10M.file bs=10240 count=1024 $ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution). No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning in shrink_delalloc. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Reviewed-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
1 parent 0f3b708
cfvidl.c
/*
* Copyright (C) ST-Ericsson AB 2010
* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cfpkt.h>
#define container_obj(layr) ((struct cfsrvl *) layr)
static int cfvidl_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfvidl_transmit(struct cflayer *layr, struct cfpkt *pkt);
struct cflayer *cfvidl_create(u8 channel_id, struct dev_info *dev_info)
{
struct cfsrvl *vid = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
if (!vid) {
pr_warn("Out of memory\n");
return NULL;
}
caif_assert(offsetof(struct cfsrvl, layer) == 0);
memset(vid, 0, sizeof(struct cfsrvl));
cfsrvl_init(vid, channel_id, dev_info, false);
vid->layer.receive = cfvidl_receive;
vid->layer.transmit = cfvidl_transmit;
snprintf(vid->layer.name, CAIF_LAYER_NAME_SZ - 1, "vid1");
return &vid->layer;
}
static int cfvidl_receive(struct cflayer *layr, struct cfpkt *pkt)
{
u32 videoheader;
if (cfpkt_extr_head(pkt, &videoheader, 4) < 0) {
pr_err("Packet is erroneous!\n");
cfpkt_destroy(pkt);
return -EPROTO;
}
return layr->up->receive(layr->up, pkt);
}
static int cfvidl_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
struct cfsrvl *service = container_obj(layr);
struct caif_payload_info *info;
u32 videoheader = 0;
int ret;
if (!cfsrvl_ready(service, &ret))
return ret;
cfpkt_add_head(pkt, &videoheader, 4);
/* Add info for MUX-layer to route the packet out */
info = cfpkt_info(pkt);
info->channel_id = service->layer.id;
info->dev_info = &service->dev_info;
ret = layr->dn->transmit(layr->dn, pkt);
if (ret < 0)
cfpkt_extr_head(pkt, &videoheader, 4);
return ret;
}
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