From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C642D42BE95 for ; Tue, 14 Jul 2026 21:33:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784064841; cv=none; b=jT4u8cp0LQAxndMP9oBuGQ+1k5GdiXb3ryCb7/y2KkmVmw7LIKa65iTX8e363HUDOyGgnJUskJoZWdDdln4irDhgKXtGtF8HVZD9/LVFgLdzjamRQ0Mz0xjbRRnT7L98xduCZqiK8FUbtdh296UPGfLYP2w5ndbcMQCHRFKCCTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784064841; c=relaxed/simple; bh=tb1NJ6THbO4fGAOt71qmHzyuduWdHm5vzycR/NKaFuI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PANNqwZYC8v2F8PrIS+ncP3E1gavxUQwJ26P6AuSs84DSVWslRHXZWcNS36U9OUYOiR5tQYMUrJq4AL7AIpV8lDn0zP37ZI1J4+Hnlu17q4E/Rwt2q7t7K3nD7G10PpQZSzRJZD7qgUfCfuksyZODyxJ+LoZdqgvAJz7bh2AclY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=SLrF5G+b; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SLrF5G+b" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-2c7c61b5292so21360095ad.0 for ; Tue, 14 Jul 2026 14:33:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1784064837; x=1784669637; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=zebbIro5mkXbuDBJ5TKnPBr9hFGew4CMfA/H27lS0KU=; b=SLrF5G+b5i9n/3C+1ZCCGVOL+lo2aSb4ZZhaf/rOZiKtc9rVJfvZKeHs2nrXG+wB3x tiCGoJwbkDuR/llcQ3wcdd1xxS9UcpyE8YlGZjA9fiKSz7ICkEK8V3rFElngGU3OTq6v Iy8hsiYVV83MwrwEjbBXfpgu3CQPHa11v8Uf+n5T9Hoz05Zp6NdbU/4uzpe+B5JVU6gN S5cesmj/yjPfUXsPIf29kOL9A4rHxMDZhPI5f2vKUsMj9lCCFPyEFzAPF7sQWd/y+hA1 jzCX2Gnl+XvAR7uu/KLQXeM78j3wMGuS6xo/xfxQk911dNDqI4Vn+8B7AwMYQbw0Y661 b08A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784064837; x=1784669637; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=zebbIro5mkXbuDBJ5TKnPBr9hFGew4CMfA/H27lS0KU=; b=Ri+uf90pmSfxdCH3d12CGps3li81wgUTDYykwrarX9ODnPEg593EGk79r9s6TEJ/jT oGH8GBiVUGSOo+qKjoxLCxnWnvrH2vTro4N1LtQPJliiWaerx1sNtBMjgdzuB+J6EVtT rZc/KijCp5VnAji5MfLhB0c5ZyRT5VxV6h/v3MkAFq8GwkL8JrPDb1xeHKoQWZICxGU8 NN7nzYXYbah2uBpIasv61FfG2C+6IOf4+M7QwWBUYYr1G7NjlwcCZx1AzhHoQENNiORp q0Ak5fzrpfCpyGsuxhQIkJ9g93DiReOXK2q7Yfwn789K/0eTGZTpwbcbsiVBklEXYSxV WY4Q== X-Forwarded-Encrypted: i=1; AHgh+RrnSRlNQEBAT7PRUor7zZRoq6JB80HGE/z7v+cgnPMa82uTehGRE2LfJ6Ekx7SqMqAjUK4hxluihyY=@vger.kernel.org X-Gm-Message-State: AOJu0YygTyXjFm4mRdXfSsA4JaeRmUch5FAPiLUWbESiMc6HJHJqM3t+ KNSYSa6pyAvVFVZKVX1y7P5VfxtsUfOp2HXh/gPuzpwXjtE6YclHgBy8 X-Gm-Gg: AfdE7cm8jMsQIVrVl5k1hr4qZ512WQJLhZKDc8Of8SzTk/FSgJZ+yb056ED6M8xsyDE DjXnewTfuLyVlmVbp2fNxdMlR6RXoOz/jHyQWGhrnd6m2Yj+AnzRNEDqbg7w2n+KxzWDBObsDWR pdVCQAG+TfdGPvvwuRnYtRzdR4qPPIiPRVPu2mIcPfRJxZyBetrax8xwZMe9LreU9JgicurN6Lt LyYUv32057tcrAKxXb093ZCY0k5HKPoTjBUZt3K+CigAc3mRTKCa6Fo/qrlS1xqtk8n/mKGi3HW Jf5Wsh3ziwmqp7LDJmSTJy+jtPVBHZ+Q2+MNLkGjzNG/uRBO5ojBoUhry53rG4a6qc6j/Sh7gZS NYN8c5MiJHMal1dxgb+vc44mQEZ6BWg6rn0P8OJiHrdolUoQKuTBIIQUlZr5YBNVwz7JyIMV2vN 5ijiM9eQL4w1YldY2xNVZsJckEcCWR/NI9hqzaRXKWBh5O4yazj8WoTGbmPjZ7dOG6mA== X-Received: by 2002:a17:903:240c:b0:2c8:1c05:16bb with SMTP id d9443c01a7336-2ce9ec0f108mr142192545ad.24.1784064836947; Tue, 14 Jul 2026 14:33:56 -0700 (PDT) Received: from skinsburskii (c-98-225-44-182.hsd1.wa.comcast.net. [98.225.44.182]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2cea6507b5csm55058005ad.72.2026.07.14.14.33.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jul 2026 14:33:56 -0700 (PDT) Date: Tue, 14 Jul 2026 14:33:53 -0700 From: Stanislav Kinsburskii To: airlied@gmail.com, akhilesh@ee.iitb.ac.in, akpm@linux-foundation.org, corbet@lwn.net, dakr@kernel.org, david@kernel.org, jgg@ziepe.ca, kees@kernel.org, leon@kernel.org, liam@infradead.org, lizhi.hou@amd.com, ljs@kernel.org, lyude@redhat.com, maarten.lankhorst@linux.intel.com, mamin506@gmail.com, mhocko@suse.com, mripard@kernel.org, nouveau@lists.freedesktop.org, ogabbay@kernel.org, oleg@redhat.com, rppt@kernel.org, shuah@kernel.org, simona@ffwll.ch, skhan@linuxfoundation.org, surenb@google.com, tzimmermann@suse.de, vbabka@kernel.org Cc: dri-devel@lists.freedesktop.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-rdma@vger.kernel.org Subject: Re: [PATCH 2/4] fixup! drm/nouveau: use hmm_range_fault_unlocked_timeout() for SVM faults Message-ID: References: <178405975214.1082778.5193079941156341151.stgit@skinsburskii> <178406001808.1082778.17299764648397654220.stgit@skinsburskii> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <178406001808.1082778.17299764648397654220.stgit@skinsburskii> On Tue, Jul 14, 2026 at 01:13:38PM -0700, Stanislav Kinsburskii wrote: > nouveau_range_fault() now uses hmm_range_fault_unlocked_timeout() for > the HMM fault path. The timeout passed to that helper is meant to bound > HMM's internal mmu-notifier retry loop, not the whole nouveau retry loop > around mmu_interval_read_retry(). > > Pass the full relative HMM_RANGE_DEFAULT_TIMEOUT value to > hmm_range_fault_unlocked_timeout() on each attempt, and retry from the > nouveau-side mmu_interval_read_retry() check with a fresh HMM retry > budget. This lets HMM continue when it has made progress, while still > preserving a timeout for repeated notifier invalidation retries inside > one HMM fault attempt. > > This also removes the open-coded absolute deadline and remaining-time > calculation from nouveau_range_fault(). > Sashiko is right. I'll need to do it differently. There will be a v2 of this series. Thanks, Stanislav > Signed-off-by: Stanislav Kinsburskii > --- > drivers/gpu/drm/nouveau/nouveau_svm.c | 30 ++++++++++-------------------- > 1 file changed, 10 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c > index 4cfb6eb7c771..b1415c2e49fc 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_svm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c > @@ -655,8 +655,7 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm, > unsigned long hmm_flags, > struct svm_notifier *notifier) > { > - unsigned long timeout = > - jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); > + unsigned long timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); > /* Have HMM fault pages within the fault window to the GPU. */ > unsigned long hmm_pfns[1]; > struct hmm_range range = { > @@ -677,25 +676,16 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm, > range.start = notifier->notifier.interval_tree.start; > range.end = notifier->notifier.interval_tree.last + 1; > > - while (true) { > - if (time_after(jiffies, timeout)) { > - ret = -EBUSY; > - goto out; > - } > - > - ret = hmm_range_fault_unlocked_timeout(&range, > - max(timeout - jiffies, > - 1L)); > - if (ret) > - goto out; > +again: > + ret = hmm_range_fault_unlocked_timeout(&range, timeout); > + if (ret) > + goto out; > > - mutex_lock(&svmm->mutex); > - if (mmu_interval_read_retry(range.notifier, > - range.notifier_seq)) { > - mutex_unlock(&svmm->mutex); > - continue; > - } > - break; > + mutex_lock(&svmm->mutex); > + if (mmu_interval_read_retry(range.notifier, > + range.notifier_seq)) { > + mutex_unlock(&svmm->mutex); > + goto again; > } > > nouveau_hmm_convert_pfn(drm, &range, args); > >