From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752578AbeDTWNs (ORCPT ); Fri, 20 Apr 2018 18:13:48 -0400 Received: from mga14.intel.com ([192.55.52.115]:15348 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751338AbeDTWNq (ORCPT ); Fri, 20 Apr 2018 18:13:46 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,303,1520924400"; d="scan'208";a="49572128" Date: Fri, 20 Apr 2018 15:13:46 -0700 From: Rodrigo Vivi To: Jani Nikula Cc: Souptick Joarder , Matthew Wilcox , airlied@linux.ie, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH] gpu: drm: i915: Change return type to vm_fault_t Message-ID: <20180420221346.GN1310@intel.com> References: <20180417151127.GA31655@jordon-HP-15-Notebook-PC> <87h8o9g8be.fsf@intel.com> <20180417161557.GA3603@bombadil.infradead.org> <871sfdxe0r.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871sfdxe0r.fsf@intel.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 18, 2018 at 08:46:44AM +0300, Jani Nikula wrote: > On Tue, 17 Apr 2018, Souptick Joarder wrote: > > On 17-Apr-2018 9:45 PM, "Matthew Wilcox" wrote: > >> > >> On Tue, Apr 17, 2018 at 09:14:32PM +0530, Souptick Joarder wrote: > >> > Not exactly. The plan for these patches is to introduce new vm_fault_t > > type > >> > in vm_operations_struct fault handlers. It's now available in 4.17-rc1. > > We will > >> > push all the required drivers/filesystem changes through different > > maintainers > >> > to linus tree. Once everything is converted into vm_fault_t type then > > Changing > >> > it from a signed to an unsigned int causes GCC to warn about an > > assignment > >> > from an incompatible type -- int foo(void) is incompatible with > >> > unsigned int foo(void). > >> > > >> > Please refer 1c8f422059ae ("mm: change return type to vm_fault_t") in > > 4.17-rc1. > >> > >> I think this patch would be clearer if you did > >> > >> - int ret; > >> + int err; > >> + vm_fault_t ret; > >> > >> Then it would be clearer to the maintainer that you're splitting apart the > >> VM_FAULT and errno codes. > >> > >> Sorry for not catching this during initial review. > > > > Ok, I will make required changes and send v2. Sorry, even I missed this :) > > I'm afraid Daniel is closer to the truth. +1. > My bad, sorry for the noise. I opened this thread to add exactly question/noise ;). So my recommendation for some next time is to make the intention clear on the commit message itself from the begin. > > BR, > Jani. > > > > >> > >> > On Tue, Apr 17, 2018 at 8:59 PM, Jani Nikula > >> > wrote: > >> > > On Tue, 17 Apr 2018, Souptick Joarder wrote: > >> > >> Use new return type vm_fault_t for fault handler. For > >> > >> now, this is just documenting that the function returns > >> > >> a VM_FAULT value rather than an errno. Once all instances > >> > >> are converted, vm_fault_t will become a distinct type. > >> > >> > >> > >> Reference id -> 1c8f422059ae ("mm: change return type to > >> > >> vm_fault_t") > >> > >> > >> > >> Signed-off-by: Souptick Joarder > >> > >> --- > >> > >> drivers/gpu/drm/i915/i915_drv.h | 3 ++- > >> > >> drivers/gpu/drm/i915/i915_gem.c | 15 ++++++++------- > >> > >> 2 files changed, 10 insertions(+), 8 deletions(-) > >> > >> > >> > >> diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h > >> > >> index a42deeb..95b0d50 100644 > >> > >> --- a/drivers/gpu/drm/i915/i915_drv.h > >> > >> +++ b/drivers/gpu/drm/i915/i915_drv.h > >> > >> @@ -51,6 +51,7 @@ > >> > >> #include > >> > >> #include > >> > >> #include > >> > >> +#include > >> > >> > >> > >> #include "i915_params.h" > >> > >> #include "i915_reg.h" > >> > >> @@ -3363,7 +3364,7 @@ int i915_gem_wait_for_idle(struct > > drm_i915_private *dev_priv, > >> > >> unsigned int flags); > >> > >> int __must_check i915_gem_suspend(struct drm_i915_private > > *dev_priv); > >> > >> void i915_gem_resume(struct drm_i915_private *dev_priv); > >> > >> -int i915_gem_fault(struct vm_fault *vmf); > >> > >> +vm_fault_t i915_gem_fault(struct vm_fault *vmf); > >> > >> int i915_gem_object_wait(struct drm_i915_gem_object *obj, > >> > >> unsigned int flags, > >> > >> long timeout, > >> > >> diff --git a/drivers/gpu/drm/i915/i915_gem.c > > b/drivers/gpu/drm/i915/i915_gem.c > >> > >> index dd89abd..bdac690 100644 > >> > >> --- a/drivers/gpu/drm/i915/i915_gem.c > >> > >> +++ b/drivers/gpu/drm/i915/i915_gem.c > >> > >> @@ -1882,7 +1882,7 @@ int i915_gem_mmap_gtt_version(void) > >> > >> * The current feature set supported by i915_gem_fault() and thus > > GTT mmaps > >> > >> * is exposed via I915_PARAM_MMAP_GTT_VERSION (see > > i915_gem_mmap_gtt_version). > >> > >> */ > >> > >> -int i915_gem_fault(struct vm_fault *vmf) > >> > >> +vm_fault_t i915_gem_fault(struct vm_fault *vmf) > >> > >> { > >> > >> #define MIN_CHUNK_PAGES ((1 << 20) >> PAGE_SHIFT) /* 1 MiB */ > >> > >> struct vm_area_struct *area = vmf->vma; > >> > >> @@ -1895,6 +1895,7 @@ int i915_gem_fault(struct vm_fault *vmf) > >> > >> pgoff_t page_offset; > >> > >> unsigned int flags; > >> > >> int ret; > >> > >> + vm_fault_t retval; > >> > > > >> > > What's the point of changing the name? An unnecessary change. > >> > > > >> > > BR, > >> > > Jani. > >> > > > >> > >> > >> > >> /* We don't use vmf->pgoff since that has the fake offset */ > >> > >> page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT; > >> > >> @@ -2000,7 +2001,7 @@ int i915_gem_fault(struct vm_fault *vmf) > >> > >> * and so needs to be reported. > >> > >> */ > >> > >> if (!i915_terminally_wedged(&dev_priv->gpu_error)) { > >> > >> - ret = VM_FAULT_SIGBUS; > >> > >> + retval = VM_FAULT_SIGBUS; > >> > >> break; > >> > >> } > >> > >> case -EAGAIN: > >> > >> @@ -2017,21 +2018,21 @@ int i915_gem_fault(struct vm_fault *vmf) > >> > >> * EBUSY is ok: this just means that another thread > >> > >> * already did the job. > >> > >> */ > >> > >> - ret = VM_FAULT_NOPAGE; > >> > >> + retval = VM_FAULT_NOPAGE; > >> > >> break; > >> > >> case -ENOMEM: > >> > >> - ret = VM_FAULT_OOM; > >> > >> + retval = VM_FAULT_OOM; > >> > >> break; > >> > >> case -ENOSPC: > >> > >> case -EFAULT: > >> > >> - ret = VM_FAULT_SIGBUS; > >> > >> + retval = VM_FAULT_SIGBUS; > >> > >> break; > >> > >> default: > >> > >> WARN_ONCE(ret, "unhandled error in i915_gem_fault: > > %i\n", ret); > >> > >> - ret = VM_FAULT_SIGBUS; > >> > >> + retval = VM_FAULT_SIGBUS; > >> > >> break; > >> > >> } > >> > >> - return ret; > >> > >> + return retval; > >> > >> } > >> > >> > >> > >> static void __i915_gem_object_release_mmap(struct > > drm_i915_gem_object *obj) > >> > >> -- > >> > >> 1.9.1 > >> > >> > >> > > > >> > > -- > >> > > Jani Nikula, Intel Open Source Technology Center > > -- > Jani Nikula, Intel Open Source Technology Center > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx