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
fpreg.c
/*
* arch/alpha/lib/fpreg.c
*
* (C) Copyright 1998 Linus Torvalds
*/
#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
#define STT(reg,val) asm volatile ("ftoit $f"#reg",%0" : "=r"(val));
#else
#define STT(reg,val) asm volatile ("stt $f"#reg",%0" : "=m"(val));
#endif
unsigned long
alpha_read_fp_reg (unsigned long reg)
{
unsigned long val;
switch (reg) {
case 0: STT( 0, val); break;
case 1: STT( 1, val); break;
case 2: STT( 2, val); break;
case 3: STT( 3, val); break;
case 4: STT( 4, val); break;
case 5: STT( 5, val); break;
case 6: STT( 6, val); break;
case 7: STT( 7, val); break;
case 8: STT( 8, val); break;
case 9: STT( 9, val); break;
case 10: STT(10, val); break;
case 11: STT(11, val); break;
case 12: STT(12, val); break;
case 13: STT(13, val); break;
case 14: STT(14, val); break;
case 15: STT(15, val); break;
case 16: STT(16, val); break;
case 17: STT(17, val); break;
case 18: STT(18, val); break;
case 19: STT(19, val); break;
case 20: STT(20, val); break;
case 21: STT(21, val); break;
case 22: STT(22, val); break;
case 23: STT(23, val); break;
case 24: STT(24, val); break;
case 25: STT(25, val); break;
case 26: STT(26, val); break;
case 27: STT(27, val); break;
case 28: STT(28, val); break;
case 29: STT(29, val); break;
case 30: STT(30, val); break;
case 31: STT(31, val); break;
default: return 0;
}
return val;
}
#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
#define LDT(reg,val) asm volatile ("itoft %0,$f"#reg : : "r"(val));
#else
#define LDT(reg,val) asm volatile ("ldt $f"#reg",%0" : : "m"(val));
#endif
void
alpha_write_fp_reg (unsigned long reg, unsigned long val)
{
switch (reg) {
case 0: LDT( 0, val); break;
case 1: LDT( 1, val); break;
case 2: LDT( 2, val); break;
case 3: LDT( 3, val); break;
case 4: LDT( 4, val); break;
case 5: LDT( 5, val); break;
case 6: LDT( 6, val); break;
case 7: LDT( 7, val); break;
case 8: LDT( 8, val); break;
case 9: LDT( 9, val); break;
case 10: LDT(10, val); break;
case 11: LDT(11, val); break;
case 12: LDT(12, val); break;
case 13: LDT(13, val); break;
case 14: LDT(14, val); break;
case 15: LDT(15, val); break;
case 16: LDT(16, val); break;
case 17: LDT(17, val); break;
case 18: LDT(18, val); break;
case 19: LDT(19, val); break;
case 20: LDT(20, val); break;
case 21: LDT(21, val); break;
case 22: LDT(22, val); break;
case 23: LDT(23, val); break;
case 24: LDT(24, val); break;
case 25: LDT(25, val); break;
case 26: LDT(26, val); break;
case 27: LDT(27, val); break;
case 28: LDT(28, val); break;
case 29: LDT(29, val); break;
case 30: LDT(30, val); break;
case 31: LDT(31, val); break;
}
}
#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
#define STS(reg,val) asm volatile ("ftois $f"#reg",%0" : "=r"(val));
#else
#define STS(reg,val) asm volatile ("sts $f"#reg",%0" : "=m"(val));
#endif
unsigned long
alpha_read_fp_reg_s (unsigned long reg)
{
unsigned long val;
switch (reg) {
case 0: STS( 0, val); break;
case 1: STS( 1, val); break;
case 2: STS( 2, val); break;
case 3: STS( 3, val); break;
case 4: STS( 4, val); break;
case 5: STS( 5, val); break;
case 6: STS( 6, val); break;
case 7: STS( 7, val); break;
case 8: STS( 8, val); break;
case 9: STS( 9, val); break;
case 10: STS(10, val); break;
case 11: STS(11, val); break;
case 12: STS(12, val); break;
case 13: STS(13, val); break;
case 14: STS(14, val); break;
case 15: STS(15, val); break;
case 16: STS(16, val); break;
case 17: STS(17, val); break;
case 18: STS(18, val); break;
case 19: STS(19, val); break;
case 20: STS(20, val); break;
case 21: STS(21, val); break;
case 22: STS(22, val); break;
case 23: STS(23, val); break;
case 24: STS(24, val); break;
case 25: STS(25, val); break;
case 26: STS(26, val); break;
case 27: STS(27, val); break;
case 28: STS(28, val); break;
case 29: STS(29, val); break;
case 30: STS(30, val); break;
case 31: STS(31, val); break;
default: return 0;
}
return val;
}
#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
#define LDS(reg,val) asm volatile ("itofs %0,$f"#reg : : "r"(val));
#else
#define LDS(reg,val) asm volatile ("lds $f"#reg",%0" : : "m"(val));
#endif
void
alpha_write_fp_reg_s (unsigned long reg, unsigned long val)
{
switch (reg) {
case 0: LDS( 0, val); break;
case 1: LDS( 1, val); break;
case 2: LDS( 2, val); break;
case 3: LDS( 3, val); break;
case 4: LDS( 4, val); break;
case 5: LDS( 5, val); break;
case 6: LDS( 6, val); break;
case 7: LDS( 7, val); break;
case 8: LDS( 8, val); break;
case 9: LDS( 9, val); break;
case 10: LDS(10, val); break;
case 11: LDS(11, val); break;
case 12: LDS(12, val); break;
case 13: LDS(13, val); break;
case 14: LDS(14, val); break;
case 15: LDS(15, val); break;
case 16: LDS(16, val); break;
case 17: LDS(17, val); break;
case 18: LDS(18, val); break;
case 19: LDS(19, val); break;
case 20: LDS(20, val); break;
case 21: LDS(21, val); break;
case 22: LDS(22, val); break;
case 23: LDS(23, val); break;
case 24: LDS(24, val); break;
case 25: LDS(25, val); break;
case 26: LDS(26, val); break;
case 27: LDS(27, val); break;
case 28: LDS(28, val); break;
case 29: LDS(29, val); break;
case 30: LDS(30, val); break;
case 31: LDS(31, val); break;
}
}
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