Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793976430; b=akpDTVaeIDQRoyMV+mU3ezh7oZXetapASVaGweBLVAP8mYp6cIaW3NwtYQcB6WlGSvCH wqI9RONjAZ7xc4Ttw7LndOs0wmhRWoxkfP2H76T9cHYd2RfnsPgq9tkV0AGJ1wQhOX9sl xAmLl4N1z8b0XxVaHVHYnQDmvECWzXHlUeVJ48I6HbtMlVETUkEZ/b4M7vsoJKkKOrf9U mczcP8H5r+hHFv73ULi3CUSJFx7n6/nGzdbfUbonXYvWSc5vzw/JMkbisxPW6SslhY47e yiJqDQt/i35yl3iGoLTzr5sNfvSMQuZSpGr3NSN1SmJcr+UiFmdKIoKVJnqSykwvqCA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793976430; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=Uhnd/cXF44dbuXcqe4bAtulK5gcsaTe6drW+FaFIL0g=; b=MPivPohOqAFv2kQsBqV08oyvEpllBjmly8ZfrX35C+tGVyxyFhg9ZO05Q1y2gPBHbNof sz0qs3laSvMpa65xrzwKfDJ08JCris3ATHg+FqoAOyLkuKKxLr+dXcer1GPlVRLcfJF/J vWQg9/6OyGxOV3ZVEmzNDqNRGAlzAjG5F9U2JDrX6rGb+86DpxelZoP8XpYVafcaVFvOS DTAQUisB9GruPMoOjn7ew8NxJPoDpIwguTWuvxAGU9Bs3Exf/9C68VTuH9Y7L2B1crQVP m3sd6df4/ejwY+dipmf4rFOCZEW1YZRdUwQMggGvz9+BBATTQ0ex+6aUTgXLK9RsLOg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MP9jaj6U; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85A38606A331 for ; Fri, 6 Nov 2026 14:47:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MP9jaj6U Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20EA41F0089F; Fri, 6 Nov 2026 14:47:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793976430; bh=Uhnd/cXF44dbuXcqe4bAtulK5gcsaTe6drW+FaFIL0g=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MP9jaj6UB+o7zwK+E9/SXs5EICFWSr0J+v14xB2r2AtxJneZMrfbGSA+zicqZc1WQ bQHHF8F+2Bg9jZVZHQ4xi+Y8xo8rqIPoHJjhfidu6+0ICVT7x+330aGu3rOYLiKZfk JUII2sFX1ps/ynXhSG7r/LByg4ZwJRm3CRtZRtXuSxMdgntwTZXvWBZpqLsXN/mvbu 6vcZwjgojmenILXfpoWIoSBERZ5FsyWr4kiO5tagW0XemkHq4MJ/kRJxkX9d05PkUQ BrnLLlAmR9nuzKPkY/cwGFMU7UuUoqlI+T2HFyn2ceAUfjuS8Dv9cnc1m3Np4GGKGz qU/K4xxsaijZw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 06/15] lib/lz4: backport upstream's aarch64 fast decode loop enablement Reply-To: sashiko-reviews@lists.linux.dev To: "Michal Wilczynski" Cc: linux-s390@vger.kernel.org, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261106-lz4-vendor-upstream-v2-6-ee04c3f0d7dc@samsung.com> References: <20261106-lz4-vendor-upstream-v2-0-ee04c3f0d7dc@samsung.com> <20261106-lz4-vendor-upstream-v2-6-ee04c3f0d7dc@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 06 Nov 2026 14:47:09 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > v1.10.0 leaves LZ4_FAST_DEC_LOOP off for aarch64 built with clang, after > a slowdown reported on some Android phones in 2019 (upstream PR #707). > An arm64 kernel built with clang therefore decodes with the slower loop. >=20 > Upstream has since enabled it for all aarch64, in three unreleased > commits: >=20 > commit 0aa33884faf5 ("[LZ4] Limit disabling LZ4_FAST_DEC_LOOP to aarch64+= clang+android") > commit 51f8af506b4a ("Fix missing endif") > commit ed86bc1ed802 ("AArch64: Enable LZ4_FAST_DEC_LOOP for Android") >=20 > Arm measured +3.5% to +15.6% on Cortex-A510 to X4 with clang. Take the > lz4.c hunks of all three. This goes away at the next re-sync. >=20 > Signed-off-by: Michal Wilczynski Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261106-lz4-vendor= -upstream-v2-0-ee04c3f0d7dc@samsung.com?part=3D6