Commit aa182e64 authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner

Revert "xfs: block allocation work needs to be kswapd aware"

This reverts commit 1f6d6482.

This commit resulted in regressions in performance in low
memory situations where kswapd was doing writeback of delayed
allocation blocks. It resulted in significant parallelism of the
kswapd work and with the special kswapd flags meant that hundreds of
active allocation could dip into kswapd specific memory reserves and
avoid being throttled. This cause a large amount of performance
variation, as well as random OOM-killer invocations that didn't
previously exist.
Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent a497c3ba
......@@ -258,23 +258,14 @@ xfs_bmapi_allocate_worker(
struct xfs_bmalloca *args = container_of(work,
struct xfs_bmalloca, work);
unsigned long pflags;
unsigned long new_pflags = PF_FSTRANS;
/*
* we are in a transaction context here, but may also be doing work
* in kswapd context, and hence we may need to inherit that state
* temporarily to ensure that we don't block waiting for memory reclaim
* in any way.
*/
if (args->kswapd)
new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
current_set_flags_nested(&pflags, new_pflags);
/* we are in a transaction context here */
current_set_flags_nested(&pflags, PF_FSTRANS);
args->result = __xfs_bmapi_allocate(args);
complete(args->done);
current_restore_flags_nested(&pflags, new_pflags);
current_restore_flags_nested(&pflags, PF_FSTRANS);
}
/*
......@@ -293,7 +284,6 @@ xfs_bmapi_allocate(
args->done = &done;
args->kswapd = current_is_kswapd();
INIT_WORK_ONSTACK(&args->work, xfs_bmapi_allocate_worker);
queue_work(xfs_alloc_wq, &args->work);
wait_for_completion(&done);
......
......@@ -50,13 +50,12 @@ struct xfs_bmalloca {
xfs_extlen_t total; /* total blocks needed for xaction */
xfs_extlen_t minlen; /* minimum allocation size (blocks) */
xfs_extlen_t minleft; /* amount must be left after alloc */
bool eof; /* set if allocating past last extent */
bool wasdel; /* replacing a delayed allocation */
bool userdata;/* set if is user data */
bool aeof; /* allocated space at eof */
bool conv; /* overwriting unwritten extents */
bool stack_switch;
bool kswapd; /* allocation in kswapd context */
char eof; /* set if allocating past last extent */
char wasdel; /* replacing a delayed allocation */
char userdata;/* set if is user data */
char aeof; /* allocated space at eof */
char conv; /* overwriting unwritten extents */
char stack_switch;
int flags;
struct completion *done;
struct work_struct work;
......
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