From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77C17225762; Wed, 27 Aug 2025 18:02:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756317771; cv=pass; b=n+1toI2uLUqkdxfQQpfdrch93Jvw8RZEN4LQFbeUzKAdxaXJFmODWu2kakKFFNmQUcxe0tPpKVFqS/Tq5YCs7CPyPW9Fb4cUvgDZ11oBczkBm8y+l+5u48r2wNS3128P23nkopc+EYBUuhEqaZIRITDwrOVFQHGtIb966uba824= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756317771; c=relaxed/simple; bh=V6MwqDZYp4KXZoHxeXb4Ga52iDgtT9V7NJZ8rlaumRw=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=aXmzCO3evWrnSv8qq9dfaadLbAvTiq3HJDmM+13eWHrNGOpb4Qo88NTxklMgMxNvTIQ1Ol8Rwj6104boe3I/W59SDap18WxTN3cCz0uUtsxaP+FWa8j8INJ2YT2qzPbTFQcO4hEcWdg7udZlo4/HItcOwifojOgSObb+0i4znq8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b=Xgh4A9rd; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b="Xgh4A9rd" ARC-Seal: i=1; a=rsa-sha256; t=1756317750; cv=none; d=zohomail.com; s=zohoarc; b=YOsEPVwZd8mB++6sUmx5Dkh6c0lPYR8zHtIwGNMyNYxnfMv9JvvTM1aT8Tbn0Naysy5A1RbiLh1aLPqYoFcPZFdyfxDvdaBHk7RFgcO2y7Vjen45+zGZ8Y0BX4yxW3hvnpjaLNWIxVYnifaSc0kE0dU5PWfmZge4A5EIc5OHBhk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1756317750; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=/C8OJPYgzbnrNpiyIgEQUTiiJPNNtcwftn4jSEMBx1Q=; b=W0CMmQH7k4DO0z+kPBIKYtikqwdxAxvEyRuGM3logQibKIbPNHmUJDUmhVlL16XAbiqROPEVdRaMemO4K9ifa2b7mC7LSyF3mFNRqxDFIWP7isiigXYbf784/k4OtwhpZ7H6jDgBxQSFCpbDUuD9EXTQCvfNV5AZMQepdP8aeOQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=daniel.almeida@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1756317750; s=zohomail; d=collabora.com; i=daniel.almeida@collabora.com; h=Content-Type:Mime-Version:Subject:Subject:From:From:In-Reply-To:Date:Date:Cc:Cc:Content-Transfer-Encoding:Message-Id:Message-Id:References:To:To:Reply-To; bh=/C8OJPYgzbnrNpiyIgEQUTiiJPNNtcwftn4jSEMBx1Q=; b=Xgh4A9rdbSSKm02jKckKCsEe6UfpDw3mJ/udn7dogx1qTuMIblOUuyBtwQ/ZWbjj vNSVSTIye81sG97cy6ARS++TlWUz7qNIGqyxYOxR3VlFJ4+/OGu6lIAV9b20izozPXI wF4jJ201xeOQzjDZXKOthOQmQazCSAGH8l8UxsKQ= Received: by mx.zohomail.com with SMTPS id 1756317747818761.8503283605801; Wed, 27 Aug 2025 11:02:27 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.700.81\)) Subject: Re: [PATCH v6 18/18] rnull: add soft-irq completion support From: Daniel Almeida In-Reply-To: <20250822-rnull-up-v6-16-v6-18-ec65006e2f07@kernel.org> Date: Wed, 27 Aug 2025 15:02:12 -0300 Cc: Boqun Feng , Miguel Ojeda , Alex Gaynor , Gary Guo , =?utf-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Alice Ryhl , Trevor Gross , Danilo Krummrich , Jens Axboe , Breno Leitao , linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <2C68673E-5A65-4BCF-ADE4-8ED33370546C@collabora.com> References: <20250822-rnull-up-v6-16-v6-0-ec65006e2f07@kernel.org> <20250822-rnull-up-v6-16-v6-18-ec65006e2f07@kernel.org> To: Andreas Hindborg X-Mailer: Apple Mail (2.3826.700.81) X-ZohoMailClient: External > On 22 Aug 2025, at 09:14, Andreas Hindborg = wrote: >=20 > rnull currently only supports direct completion. Add option for = completing > requests across CPU nodes via soft IRQ or IPI. >=20 > Reviewed-by: Alice Ryhl > Signed-off-by: Andreas Hindborg > --- > drivers/block/rnull/configfs.rs | 59 = +++++++++++++++++++++++++++++++++++++++-- > drivers/block/rnull/rnull.rs | 32 ++++++++++++++-------- > 2 files changed, 78 insertions(+), 13 deletions(-) >=20 > diff --git a/drivers/block/rnull/configfs.rs = b/drivers/block/rnull/configfs.rs > index 46710a1e1af4..8498e9bae6fd 100644 > --- a/drivers/block/rnull/configfs.rs > +++ b/drivers/block/rnull/configfs.rs > @@ -1,7 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0 >=20 > use super::{NullBlkDevice, THIS_MODULE}; > -use core::fmt::Write; > +use core::fmt::{Display, Write}; > use kernel::{ > block::mq::gen_disk::{GenDisk, GenDiskBuilder}, > c_str, > @@ -36,7 +36,7 @@ impl AttributeOperations<0> for Config { >=20 > fn show(_this: &Config, page: &mut [u8; PAGE_SIZE]) -> = Result { > let mut writer =3D kernel::str::Formatter::new(page); > - writer.write_str("blocksize,size,rotational\n")?; > + writer.write_str("blocksize,size,rotational,irqmode\n")?; > Ok(writer.bytes_written()) > } > } > @@ -58,6 +58,7 @@ fn make_group( > blocksize: 1, > rotational: 2, > size: 3, > + irqmode: 4, > ], > }; >=20 > @@ -72,6 +73,7 @@ fn make_group( > rotational: false, > disk: None, > capacity_mib: 4096, > + irq_mode: IRQMode::None, > name: name.try_into()?, > }), > }), > @@ -79,6 +81,34 @@ fn make_group( > } > } >=20 > +#[derive(Debug, Clone, Copy)] > +pub(crate) enum IRQMode { > + None, > + Soft, > +} > + > +impl TryFrom for IRQMode { > + type Error =3D kernel::error::Error; > + > + fn try_from(value: u8) -> Result { > + match value { > + 0 =3D> Ok(Self::None), > + 1 =3D> Ok(Self::Soft), > + _ =3D> Err(EINVAL), > + } > + } > +} > + > +impl Display for IRQMode { > + fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> = core::fmt::Result { > + match self { > + Self::None =3D> f.write_str("0")?, > + Self::Soft =3D> f.write_str("1")?, > + } > + Ok(()) > + } > +} > + > #[pin_data] > pub(crate) struct DeviceConfig { > #[pin] > @@ -92,6 +122,7 @@ struct DeviceConfigInner { > block_size: u32, > rotational: bool, > capacity_mib: u64, > + irq_mode: IRQMode, > disk: Option>, > } >=20 > @@ -121,6 +152,7 @@ fn store(this: &DeviceConfig, page: &[u8]) -> = Result { > guard.block_size, > guard.rotational, > guard.capacity_mib, > + guard.irq_mode, > )?); > guard.powered =3D true; > } else if guard.powered && !power_op { > @@ -205,3 +237,26 @@ fn store(this: &DeviceConfig, page: &[u8]) -> = Result { > Ok(()) > } > } > + > +#[vtable] > +impl configfs::AttributeOperations<4> for DeviceConfig { > + type Data =3D DeviceConfig; > + > + fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> = Result { > + let mut writer =3D kernel::str::Formatter::new(page); > + writer.write_fmt(fmt!("{}\n", this.data.lock().irq_mode))?; > + Ok(writer.bytes_written()) > + } > + > + fn store(this: &DeviceConfig, page: &[u8]) -> Result { > + if this.data.lock().powered { > + return Err(EBUSY); > + } > + > + let text =3D core::str::from_utf8(page)?.trim(); > + let value =3D text.parse::().map_err(|_| EINVAL)?; > + > + this.data.lock().irq_mode =3D IRQMode::try_from(value)?; > + Ok(()) > + } > +} > diff --git a/drivers/block/rnull/rnull.rs = b/drivers/block/rnull/rnull.rs > index a19c55717c4f..1ec694d7f1a6 100644 > --- a/drivers/block/rnull/rnull.rs > +++ b/drivers/block/rnull/rnull.rs > @@ -4,6 +4,7 @@ >=20 > mod configfs; >=20 > +use configfs::IRQMode; > use kernel::{ > block::{ > self, > @@ -53,35 +54,44 @@ fn new( > block_size: u32, > rotational: bool, > capacity_mib: u64, > + irq_mode: IRQMode, > ) -> Result> { > let tagset =3D Arc::pin_init(TagSet::new(1, 256, 1), = GFP_KERNEL)?; >=20 > + let queue_data =3D Box::new(QueueData { irq_mode }, = GFP_KERNEL)?; > + > gen_disk::GenDiskBuilder::new() > .capacity_sectors(capacity_mib << (20 - = block::SECTOR_SHIFT)) > .logical_block_size(block_size)? > .physical_block_size(block_size)? > .rotational(rotational) > - .build(fmt!("{}", name.to_str()?), tagset, ()) > + .build(fmt!("{}", name.to_str()?), tagset, queue_data) > } > } >=20 > +struct QueueData { > + irq_mode: IRQMode, > +} > + > #[vtable] > impl Operations for NullBlkDevice { > - type QueueData =3D (); > + type QueueData =3D KBox; >=20 > #[inline(always)] > - fn queue_rq(_queue_data: (), rq: ARef>, = _is_last: bool) -> Result { > - mq::Request::end_ok(rq) > - .map_err(|_e| kernel::error::code::EIO) > - // We take no refcounts on the request, so we expect to = be able to > - // end the request. The request reference must be unique = at this > - // point, and so `end_ok` cannot fail. > - .expect("Fatal error - expected to be able to end = request"); Same comment here as on the last patch. Otherwise LGTM. > - > + fn queue_rq(queue_data: &QueueData, rq: ARef>, = _is_last: bool) -> Result { > + match queue_data.irq_mode { > + IRQMode::None =3D> mq::Request::end_ok(rq) > + .map_err(|_e| kernel::error::code::EIO) > + // We take no refcounts on the request, so we expect = to be able to > + // end the request. The request reference must be = unique at this > + // point, and so `end_ok` cannot fail. > + .expect("Fatal error - expected to be able to end = request"), > + IRQMode::Soft =3D> mq::Request::complete(rq), > + } > Ok(()) > } >=20 > - fn commit_rqs(_queue_data: ()) {} > + fn commit_rqs(_queue_data: &QueueData) {} >=20 > fn complete(rq: ARef>) { > mq::Request::end_ok(rq) >=20 > --=20 > 2.47.2 >=20 >=20 >=20