3ccadbce85
vfs_kernel_mount() modifies the passed in mount options, leaving us with "huge", instead of "huge=within_size". Normally this shouldn't matter with the usual module load/unload flow, however with the core_hotunplug IGT we are hitting the following, when re-probing the memory regions: i915 0000:00:02.0: [drm] Transparent Hugepage mode 'huge' tmpfs: Bad value for 'huge' [drm] Unable to create a private tmpfs mount, hugepage support will be disabled(-22). References: https://gitlab.freedesktop.org/drm/intel/-/issues/4651 Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211126110843.2028582-1-matthew.auld@intel.com
60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
/*
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* SPDX-License-Identifier: MIT
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*
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* Copyright © 2017 Intel Corporation
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*/
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#include <linux/fs.h>
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#include <linux/mount.h>
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#include "i915_drv.h"
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#include "i915_gemfs.h"
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int i915_gemfs_init(struct drm_i915_private *i915)
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{
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char huge_opt[] = "huge=within_size"; /* r/w */
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struct file_system_type *type;
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struct vfsmount *gemfs;
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char *opts;
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type = get_fs_type("tmpfs");
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if (!type)
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return -ENODEV;
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/*
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* By creating our own shmemfs mountpoint, we can pass in
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* mount flags that better match our usecase.
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*
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* One example, although it is probably better with a per-file
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* control, is selecting huge page allocations ("huge=within_size").
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* However, we only do so to offset the overhead of iommu lookups
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* due to bandwidth issues (slow reads) on Broadwell+.
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*/
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opts = NULL;
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if (intel_vtd_active()) {
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if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
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opts = huge_opt;
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drm_info(&i915->drm,
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"Transparent Hugepage mode '%s'\n",
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opts);
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} else {
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drm_notice(&i915->drm,
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"Transparent Hugepage support is recommended for optimal performance when IOMMU is enabled!\n");
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}
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}
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gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name, opts);
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if (IS_ERR(gemfs))
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return PTR_ERR(gemfs);
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i915->mm.gemfs = gemfs;
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return 0;
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}
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void i915_gemfs_fini(struct drm_i915_private *i915)
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{
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kern_unmount(i915->mm.gemfs);
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}
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