linux-kernel - [PATCH] docs/core-api: memory-allocation: GFP_NOWAIT doesn't need __GFP

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Message-Id: <20240729140127.244606-1-Dave.Martin@arm.com>
Date: Mon, 29 Jul 2024 15:01:27 +0100
From: Dave Martin <Dave.Martin@....com>
To: linux-kernel@...r.kernel.org
Cc: linux-doc@...r.kernel.org,
	Jonathan Corbet <corbet@....net>,
	Matthew Wilcox <willy@...radead.org>,
	Mike Rapoport <rppt@...nel.org>
Subject: [PATCH] docs/core-api: memory-allocation: GFP_NOWAIT doesn't need __GFP_NOWARN

Since v6.8 the definition of GFP_NOWAIT has implied __GFP_NOWARN,
so it is now redundant to add this flag explicitly.

Update the docs to match, and emphasise the need for a fallback
when using GFP_NOWAIT.

Fixes: 16f5dfbc851b ("gfp: include __GFP_NOWARN in GFP_NOWAIT")
Signed-off-by: Dave Martin <Dave.Martin@....com>

---

Based on: v6.11-rc1

This change also evaporates the apparent typo of __GFP_NOWARN without
the underscores in the documentation, but that doesn't really feel like
it merits a dedicated patch.

Not sure if this really merits a Fixes tag, but the docmuentation
update might as well be picked into trees that have the corresponding
code change.

---
 Documentation/core-api/memory-allocation.rst | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/core-api/memory-allocation.rst b/Documentation/core-api/memory-allocation.rst
index 8b84eb4bdae7..0f19dd524323 100644
--- a/Documentation/core-api/memory-allocation.rst
+++ b/Documentation/core-api/memory-allocation.rst
@@ -45,8 +45,9 @@ here we briefly outline their recommended usage:
   * If the allocation is performed from an atomic context, e.g interrupt
     handler, use ``GFP_NOWAIT``. This flag prevents direct reclaim and
     IO or filesystem operations. Consequently, under memory pressure
-    ``GFP_NOWAIT`` allocation is likely to fail. Allocations which
-    have a reasonable fallback should be using ``GFP_NOWARN``.
+    ``GFP_NOWAIT`` allocation is likely to fail. Users of this flag need
+    to provide a suitable fallback to cope with such failures where
+    appropriate.
   * If you think that accessing memory reserves is justified and the kernel
     will be stressed unless allocation succeeds, you may use ``GFP_ATOMIC``.
   * Untrusted allocations triggered from userspace should be a subject

base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
-- 
2.34.1