[PATCH 5/6] XFS: remove congestion_wait() loop from kmem_alloc()
From: NeilBrown <hidden>
Date: 2021-09-17 03:00:12
Also in:
linux-doc, linux-ext4, linux-fsdevel, linux-mm, linux-nfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
Documentation commment in gfp.h discourages indefinite retry loops on
ENOMEM and says of __GFP_NOFAIL that it
is definitely preferable to use the flag rather than opencode
endless loop around allocator.
So remove the loop, instead specifying __GFP_NOFAIL if KM_MAYFAIL was
not given.
As we no longer have the opportunity to report a warning after some
failures, clear __GFP_NOWARN so that the default warning (rate-limited
to 1 ever 10 seconds) will be reported instead.
Signed-off-by: NeilBrown <redacted>
---
fs/xfs/kmem.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index 6f49bf39183c..575a58e61391 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c@@ -11,21 +11,14 @@ void * kmem_alloc(size_t size, xfs_km_flags_t flags) { - int retries = 0; gfp_t lflags = kmem_flags_convert(flags); - void *ptr; trace_kmem_alloc(size, flags, _RET_IP_); - do { - ptr = kmalloc(size, lflags); - if (ptr || (flags & KM_MAYFAIL)) - return ptr; - if (!(++retries % 100)) - xfs_err(NULL, - "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)", - current->comm, current->pid, - (unsigned int)size, __func__, lflags); - congestion_wait(BLK_RW_ASYNC, HZ/50); - } while (1); + if (!(flags & KM_MAYFAIL)) { + lflags |= __GFP_NOFAIL; + lflags &= ~__GFP_NOWARN; + } + + return kmalloc(size, lflags); }