[PATCH 14/15] staging: lustre: osc: Use SOFT_SYNC to urge server commit
James Simmons
jsimmons at infradead.org
Wed Apr 27 22:21:06 UTC 2016
From: Prakash Surya <surya1 at llnl.gov>
This change adds a BRW page flag, OBD_BRW_SOFT_SYNC. This flag is
intended to urge a server to commit a client's unstable pages to
stable storage. A client will add this flag to any BRW requests while
it is in a state where it has "many" unstable pages pinned in its cache.
The server, upon receiving a page with this flag set, *should* begin
an async commit. The idea being that, with the proactive async commit,
the client's pinned unstable pages will transition into a stable state
faster than they would have otherwise. Although, the server side portion
of this agreement is still unimplemented, so the OBD_BRW_SOFT_SYNC flag
will currently fall on deaf ears.
Signed-off-by: Prakash Surya <surya1 at llnl.gov>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2139
Reviewed-on: http://review.whamcloud.com/4375
Reviewed-by: Jinshan Xiong <jinshan.xiong at intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin at intel.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
.../lustre/lustre/include/lustre/lustre_idl.h | 5 +++
drivers/staging/lustre/lustre/osc/osc_cache.c | 3 ++
drivers/staging/lustre/lustre/osc/osc_internal.h | 1 +
drivers/staging/lustre/lustre/osc/osc_page.c | 29 ++++++++++++++++++++
drivers/staging/lustre/lustre/osc/osc_request.c | 3 +-
drivers/staging/lustre/lustre/ptlrpc/wiretest.c | 6 ++++
6 files changed, 46 insertions(+), 1 deletions(-)
diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
index c3565bf..26819ee 100644
--- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
+++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
@@ -1734,6 +1734,11 @@ void lustre_swab_obd_statfs(struct obd_statfs *os);
#define OBD_BRW_MEMALLOC 0x800 /* Client runs in the "kswapd" context */
#define OBD_BRW_OVER_USRQUOTA 0x1000 /* Running out of user quota */
#define OBD_BRW_OVER_GRPQUOTA 0x2000 /* Running out of group quota */
+#define OBD_BRW_SOFT_SYNC 0x4000 /* This flag notifies the server
+ * that the client is running low on
+ * space for unstable pages; asking
+ * it to sync quickly
+ */
#define OBD_OBJECT_EOF 0xffffffffffffffffULL
diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c
index 7d1c2c5..5a14bea 100644
--- a/drivers/staging/lustre/lustre/osc/osc_cache.c
+++ b/drivers/staging/lustre/lustre/osc/osc_cache.c
@@ -2437,6 +2437,9 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
return rc;
}
+ if (osc_over_unstable_soft_limit(cli))
+ brw_flags |= OBD_BRW_SOFT_SYNC;
+
oap->oap_cmd = cmd;
oap->oap_page_off = ops->ops_from;
oap->oap_count = ops->ops_to - ops->ops_from;
diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h
index 39e6138..7fad827 100644
--- a/drivers/staging/lustre/lustre/osc/osc_internal.h
+++ b/drivers/staging/lustre/lustre/osc/osc_internal.h
@@ -202,6 +202,7 @@ int osc_quotacheck(struct obd_device *unused, struct obd_export *exp,
int osc_quota_poll_check(struct obd_export *exp, struct if_quotacheck *qchk);
void osc_inc_unstable_pages(struct ptlrpc_request *req);
void osc_dec_unstable_pages(struct ptlrpc_request *req);
+int osc_over_unstable_soft_limit(struct client_obd *cli);
struct ldlm_lock *osc_dlmlock_at_pgoff(const struct lu_env *env,
struct osc_object *obj, pgoff_t index,
diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c
index 5ec5508..c29c2ea 100644
--- a/drivers/staging/lustre/lustre/osc/osc_page.c
+++ b/drivers/staging/lustre/lustre/osc/osc_page.c
@@ -346,6 +346,32 @@ int osc_page_init(const struct lu_env *env, struct cl_object *obj,
return result;
}
+int osc_over_unstable_soft_limit(struct client_obd *cli)
+{
+ long obd_upages, obd_dpages, osc_upages;
+
+ /* Can't check cli->cl_unstable_count, therefore, no soft limit */
+ if (!cli)
+ return 0;
+
+ obd_upages = atomic_read(&obd_unstable_pages);
+ obd_dpages = atomic_read(&obd_dirty_pages);
+
+ osc_upages = atomic_read(&cli->cl_unstable_count);
+
+ /*
+ * obd_max_dirty_pages is the max number of (dirty + unstable)
+ * pages allowed at any given time. To simulate an unstable page
+ * only limit, we subtract the current number of dirty pages
+ * from this max. This difference is roughly the amount of pages
+ * currently available for unstable pages. Thus, the soft limit
+ * is half of that difference. Check osc_upages to ensure we don't
+ * set SOFT_SYNC for OSCs without any outstanding unstable pages.
+ */
+ return osc_upages &&
+ obd_upages >= (obd_max_dirty_pages - obd_dpages) / 2;
+}
+
/**
* Helper function called by osc_io_submit() for every page in an immediate
* transfer (i.e., transferred synchronously).
@@ -369,6 +395,9 @@ void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
oap->oap_count = opg->ops_to - opg->ops_from;
oap->oap_brw_flags = brw_flags | OBD_BRW_SYNC;
+ if (osc_over_unstable_soft_limit(oap->oap_cli))
+ oap->oap_brw_flags |= OBD_BRW_SOFT_SYNC;
+
if (!client_is_remote(osc_export(obj)) &&
capable(CFS_CAP_SYS_RESOURCE)) {
oap->oap_brw_flags |= OBD_BRW_NOQUOTA;
diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c
index e8a80eb..df06f4f 100644
--- a/drivers/staging/lustre/lustre/osc/osc_request.c
+++ b/drivers/staging/lustre/lustre/osc/osc_request.c
@@ -1147,7 +1147,8 @@ static inline int can_merge_pages(struct brw_page *p1, struct brw_page *p2)
{
if (p1->flag != p2->flag) {
unsigned mask = ~(OBD_BRW_FROM_GRANT | OBD_BRW_NOCACHE |
- OBD_BRW_SYNC | OBD_BRW_ASYNC|OBD_BRW_NOQUOTA);
+ OBD_BRW_SYNC | OBD_BRW_ASYNC |
+ OBD_BRW_NOQUOTA | OBD_BRW_SOFT_SYNC);
/* warn if we try to combine flags that we don't know to be
* safe to combine
diff --git a/drivers/staging/lustre/lustre/ptlrpc/wiretest.c b/drivers/staging/lustre/lustre/ptlrpc/wiretest.c
index 3ffd2d9..87555e4 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/wiretest.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/wiretest.c
@@ -1639,6 +1639,12 @@ void lustre_assert_wire_constants(void)
OBD_BRW_ASYNC);
LASSERTF(OBD_BRW_MEMALLOC == 0x800, "found 0x%.8x\n",
OBD_BRW_MEMALLOC);
+ LASSERTF(OBD_BRW_OVER_USRQUOTA == 0x1000, "found 0x%.8x\n",
+ OBD_BRW_OVER_USRQUOTA);
+ LASSERTF(OBD_BRW_OVER_GRPQUOTA == 0x2000, "found 0x%.8x\n",
+ OBD_BRW_OVER_GRPQUOTA);
+ LASSERTF(OBD_BRW_SOFT_SYNC == 0x4000, "found 0x%.8x\n",
+ OBD_BRW_SOFT_SYNC);
/* Checks for struct ost_body */
LASSERTF((int)sizeof(struct ost_body) == 208, "found %lld\n",
--
1.7.1
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