Re: [PATCH RFC PKS/PMEM 51/58] kernel: Utilize new kmap_thread()
From: Eric W. Biederman <hidden>
Date: 2020-10-10 04:47:41
Also in:
amd-gfx, bpf, ceph-devel, dri-devel, intel-gfx, intel-wired-lan, io-uring, kexec, kvm, linux-bcache, linux-block, linux-btrfs, linux-cifs, linux-doc, linux-efi, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-kselftest, linux-mm, linux-mmc, linux-nfs, linux-rdma, linux-scsi, linux-um, lkml, netdev, nvdimm, target-devel, xen-devel
ira.weiny@intel.com writes:
From: Ira Weiny <ira.weiny@intel.com> This kmap() call is localized to a single thread. To avoid the over head of global PKRS updates use the new kmap_thread() call.
Acked-by: "Eric W. Biederman" <redacted>
quoted hunk
Cc: Eric Biederman <redacted> Signed-off-by: Ira Weiny <ira.weiny@intel.com> --- kernel/kexec_core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index c19c0dad1ebe..272a9920c0d6 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c@@ -815,7 +815,7 @@ static int kimage_load_normal_segment(struct kimage *image, if (result < 0) goto out; - ptr = kmap(page); + ptr = kmap_thread(page); /* Start with a clear page */ clear_page(ptr); ptr += maddr & ~PAGE_MASK;@@ -828,7 +828,7 @@ static int kimage_load_normal_segment(struct kimage *image, memcpy(ptr, kbuf, uchunk); else result = copy_from_user(ptr, buf, uchunk); - kunmap(page); + kunmap_thread(page); if (result) { result = -EFAULT; goto out;@@ -879,7 +879,7 @@ static int kimage_load_crash_segment(struct kimage *image, goto out; } arch_kexec_post_alloc_pages(page_address(page), 1, 0); - ptr = kmap(page); + ptr = kmap_thread(page); ptr += maddr & ~PAGE_MASK; mchunk = min_t(size_t, mbytes, PAGE_SIZE - (maddr & ~PAGE_MASK));@@ -895,7 +895,7 @@ static int kimage_load_crash_segment(struct kimage *image, else result = copy_from_user(ptr, buf, uchunk); kexec_flush_icache_page(page); - kunmap(page); + kunmap_thread(page); arch_kexec_pre_free_pages(page_address(page), 1); if (result) { result = -EFAULT;