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[PATCH] s390: qdio memory allocations

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Avoid memory allocation with GFP_KERNEL in qdio_establish/qdio_shutdown.  Use
memory pool instead.  (Otherwise this can lead to an I/O stall where qdio
waits for a free page and zfcp waits for end of error recovery in low memory
situations.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andreas Herrmann 2006-04-27 18:40:09 -07:00 committed by Linus Torvalds
parent 28f223782b
commit a3ae39c060
1 changed files with 24 additions and 6 deletions
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30
drivers/s390/cio/qdio.c
View file

@ -38,6 +38,7 @@
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/timer.h>
#include <linux/mempool.h>
#include <asm/ccwdev.h>
#include <asm/io.h>
@ -80,6 +81,8 @@ static int indicator_used[INDICATORS_PER_CACHELINE];
static __u32 * volatile indicators;
static __u32 volatile spare_indicator;
static atomic_t spare_indicator_usecount;
#define QDIO_MEMPOOL_SCSSC_ELEMENTS 2
static mempool_t *qdio_mempool_scssc;
static debug_info_t *qdio_dbf_setup;
static debug_info_t *qdio_dbf_sbal;
@ -2304,7 +2307,7 @@ qdio_get_ssqd_information(struct qdio_irq *irq_ptr)
QDIO_DBF_TEXT0(0,setup,"getssqd");
qdioac = 0;
ssqd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
ssqd_area = mempool_alloc(qdio_mempool_scssc, GFP_ATOMIC);
if (!ssqd_area) {
QDIO_PRINT_WARN("Could not get memory for chsc. Using all " \
"SIGAs for sch x%x.\n", irq_ptr->schid.sch_no);
@ -2364,7 +2367,7 @@ qdio_get_ssqd_information(struct qdio_irq *irq_ptr)
out:
qdio_check_subchannel_qebsm(irq_ptr, qdioac,
ssqd_area->sch_token);
free_page ((unsigned long) ssqd_area);
mempool_free(ssqd_area, qdio_mempool_scssc);
irq_ptr->qdioac = qdioac;
}
@ -2458,7 +2461,7 @@ tiqdio_set_subchannel_ind(struct qdio_irq *irq_ptr, int reset_to_zero)
virt_to_phys((volatile void *)irq_ptr->dev_st_chg_ind);
}
scssc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
scssc_area = mempool_alloc(qdio_mempool_scssc, GFP_ATOMIC);
if (!scssc_area) {
QDIO_PRINT_WARN("No memory for setting indicators on " \
"subchannel 0.%x.%x.\n",
@ -2514,7 +2517,7 @@ tiqdio_set_subchannel_ind(struct qdio_irq *irq_ptr, int reset_to_zero)
QDIO_DBF_HEX2(0,setup,&real_addr_dev_st_chg_ind,sizeof(unsigned long));
result = 0;
out:
free_page ((unsigned long) scssc_area);
mempool_free(scssc_area, qdio_mempool_scssc);
return result;
}
@ -2543,7 +2546,7 @@ tiqdio_set_delay_target(struct qdio_irq *irq_ptr, unsigned long delay_target)
if (!irq_ptr->is_thinint_irq)
return -ENODEV;
scsscf_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
scsscf_area = mempool_alloc(qdio_mempool_scssc, GFP_ATOMIC);
if (!scsscf_area) {
QDIO_PRINT_WARN("No memory for setting delay target on " \
"subchannel 0.%x.%x.\n",
@ -2581,7 +2584,7 @@ tiqdio_set_delay_target(struct qdio_irq *irq_ptr, unsigned long delay_target)
QDIO_DBF_HEX2(0,trace,&delay_target,sizeof(unsigned long));
result = 0; /* not critical */
out:
free_page ((unsigned long) scsscf_area);
mempool_free(scsscf_area, qdio_mempool_scssc);
return result;
}
@ -3780,6 +3783,16 @@ qdio_register_dbf_views(void)
return -ENOMEM;
}
static void *qdio_mempool_alloc(gfp_t gfp_mask, void *size)
{
return (void *) get_zeroed_page(gfp_mask|GFP_DMA);
}
static void qdio_mempool_free(void *element, void *size)
{
free_page((unsigned long) element);
}
static int __init
init_QDIO(void)
{
@ -3809,6 +3822,10 @@ init_QDIO(void)
qdio_add_procfs_entry();
qdio_mempool_scssc = mempool_create(QDIO_MEMPOOL_SCSSC_ELEMENTS,
qdio_mempool_alloc,
qdio_mempool_free, NULL);
if (tiqdio_check_chsc_availability())
QDIO_PRINT_ERR("Not all CHSCs supported. Continuing.\n");
@ -3824,6 +3841,7 @@ cleanup_QDIO(void)
qdio_remove_procfs_entry();
qdio_release_qdio_memory();
qdio_unregister_dbf_views();
mempool_destroy(qdio_mempool_scssc);
printk("qdio: %s: module removed\n",version);
}