From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 ABA721624C9 for ; Fri, 4 Apr 2025 14:52:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743778361; cv=none; b=q5NvIwAdT8vtr+oKd1mIBJBGeuh+qxZwfkhxEg5V5RxsTdg/zub+8bSgg6dfhVsWwlLBWCabS2WbwcMPCYyA31/3PsErqw8ZcRiAi6HQjGaByq+8zTwAmgN6pIwk0bdGFQLd3L44eL3lMvjdpelMNYULD646SN1dscDxxIl641o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743778361; c=relaxed/simple; bh=HQEwVFo23Mr3erq7OYuxzmfb7ImgX/7WpQUlZtxKNVw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=fyD/rKXlEVHaiy+r/CKhqwCpAFGtSo+WtgzVQF71N4IHCMPR3hNKgcMiImJqYk1D1+KMTigH+79PUo7zfbQHkU866/8+L1FJuSReVWiuLsrHQ7fy6ar6xXACHRU5Ve/n/6X6bTKDDapKEmk5+mEYAck7pzcZx0XRiobZPIK2ovI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=AK5dZbe5; arc=none smtp.client-ip=148.251.105.195 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 (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="AK5dZbe5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1743778357; bh=HQEwVFo23Mr3erq7OYuxzmfb7ImgX/7WpQUlZtxKNVw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=AK5dZbe5u1Q8thHivk2etDFByqBQib3ESC+QWMrdfiTL8JOQz527MQUAa4mO8RlPR e9mHhS4X6Rpk2yMAONLbgRdUMPeY6/ECC6mu6tDzyDSquI8DVUW/zaoITnBBQQso1M xRaUgreQgne87px2bCaUEgdhr3iWNWd6sCdMnkDb89twFURpogR1aHPggVOqQ2x7SW lJUfpBLxujR6NsosDOh9c7d0K5shN/3NspDRkmHZantnMfIluOYaFQolJFNOg3waDR qg08P3rtOxfBjA+HNsrT18riIHeW3GpH37mWFnDuCBneJRjUP0qEmM2ygT/bi+EaUw 4RRnoMre1bt0Q== Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 2E25117E0B0B; Fri, 4 Apr 2025 16:52:37 +0200 (CEST) Date: Fri, 4 Apr 2025 16:52:33 +0200 From: Boris Brezillon To: Thomas Zimmermann Cc: Dmitry Osipenko , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Christian =?UTF-8?B?S8O2bmln?= , Gerd Hoffmann , Qiang Yu , Steven Price , Frank Binns , Matt Coster , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCH v20 09/10] drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin Message-ID: <20250404165233.139814ee@collabora.com> In-Reply-To: <29cfb98b-fe27-4243-abe4-ce66aa504573@suse.de> References: <20250322212608.40511-1-dmitry.osipenko@collabora.com> <20250322212608.40511-10-dmitry.osipenko@collabora.com> <710cdbd4-2c6e-48b7-b12b-972ab6d12abf@collabora.com> <20250402152102.01d9cfee@collabora.com> <20250403105053.788b0f6e@collabora.com> <29cfb98b-fe27-4243-abe4-ce66aa504573@suse.de> Organization: Collabora X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 4 Apr 2025 10:01:50 +0200 Thomas Zimmermann wrote: > >> In your case, vmap an pin both intent to hold the shmem pages in memory. > >> They might be build on top of the same implementation, but one should > >> not be implemented with the other because of their different meanings. > > But that's not what we do, is it? Sure, in drm_gem_shmem_vmap_locked(), > > we call drm_gem_shmem_pin_locked(), but that's an internal function to > > make sure the pages are allocated and stay around until > > drm_gem_shmem_vunmap_locked() is called. > > > > I guess we could rename pin_count into hard_refcount or > > page_residency_count or xxx_count, and change the pin/unpin_locked() > > function names accordingly, but that's just a naming detail, it doesn't > > force you to call drm_gem_pin() to vmap() your GEM, it's something we > > do internally. > > Such a rename would be much appreciated. page_residency_count seems > appropriate. On a second thought, I think I prefer 'unevictable_count/inc_unevictable()/dec_unevictable()'. But looking at the gem-vram changes you just posted, it looks like gem-shmem is not the only one to use the term 'pin' for this page pinning thing, so if we go and plan for a rename, I'd rather make it DRM-wide than gem-shmem being the outlier yet again :-).