diff options
| author | Jeff Roberson <jeff@FreeBSD.org> | 2018-02-20 00:06:07 +0000 |
|---|---|---|
| committer | Jeff Roberson <jeff@FreeBSD.org> | 2018-02-20 00:06:07 +0000 |
| commit | 06220fa737d9e3bf45f1a9b716425fcacb5c4d64 (patch) | |
| tree | 938bdd0941d47e048a087ed6be7f8e735dd83661 /sys/sys/buf.h | |
| parent | 4b6da14cfa1ee9b815f80ca8077839f65bb6b3be (diff) | |
| download | src-06220fa737d9e3bf45f1a9b716425fcacb5c4d64.tar.gz src-06220fa737d9e3bf45f1a9b716425fcacb5c4d64.zip | |
Further parallelize the buffer cache.
Provide multiple clean queues partitioned into 'domains'. Each domain manages
its own bufspace and has its own bufspace daemon. Each domain has a set of
subqueues indexed by the current cpuid to reduce lock contention on the cleanq.
Refine the sleep/wakeup around the bufspace daemon to use atomics as much as
possible.
Add a B_REUSE flag that is used to requeue bufs during the scan to approximate
LRU rather than locking the queue on every use of a frequently accessed buf.
Implement bufspace_reserve with only atomic_fetchadd to avoid loop restarts.
Reviewed by: markj
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14274
Notes
Notes:
svn path=/head/; revision=329612
Diffstat (limited to 'sys/sys/buf.h')
| -rw-r--r-- | sys/sys/buf.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/sys/sys/buf.h b/sys/sys/buf.h index 0875cde64b16..c9b2eeaed5b2 100644 --- a/sys/sys/buf.h +++ b/sys/sys/buf.h @@ -112,7 +112,9 @@ struct buf { off_t b_offset; /* Offset into file. */ TAILQ_ENTRY(buf) b_bobufs; /* (V) Buffer's associated vnode. */ uint32_t b_vflags; /* (V) BV_* flags */ - unsigned short b_qindex; /* (Q) buffer queue index */ + uint8_t b_qindex; /* (Q) buffer queue index */ + uint8_t b_domain; /* (Q) buf domain this resides in */ + uint16_t b_subqueue; /* (Q) per-cpu q if any */ uint32_t b_flags; /* B_* flags. */ b_xflags_t b_xflags; /* extra flags */ struct lock b_lock; /* Buffer lock */ @@ -217,7 +219,7 @@ struct buf { #define B_DONE 0x00000200 /* I/O completed. */ #define B_EINTR 0x00000400 /* I/O was interrupted */ #define B_NOREUSE 0x00000800 /* Contents not reused once released. */ -#define B_00001000 0x00001000 /* Available flag. */ +#define B_REUSE 0x00001000 /* Contents reused, second chance. */ #define B_INVAL 0x00002000 /* Does not contain valid info. */ #define B_BARRIER 0x00004000 /* Write this and all preceding first. */ #define B_NOCACHE 0x00008000 /* Do not cache block after use. */ @@ -241,7 +243,7 @@ struct buf { #define PRINT_BUF_FLAGS "\20\40remfree\37cluster\36vmio\35ram\34managed" \ "\33paging\32infreecnt\31nocopy\30b23\27relbuf\26b21\25b20" \ "\24b19\23b18\22clusterok\21malloc\20nocache\17b14\16inval" \ - "\15b12\14noreuse\13eintr\12done\11b8\10delwri" \ + "\15reuse\14noreuse\13eintr\12done\11b8\10delwri" \ "\7validsuspwrt\6cache\5deferred\4direct\3async\2needcommit\1age" /* |