From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin Cross Subject: [PATCH 3/3] seq_file: convert seq buffer to vmalloc Date: Thu, 22 Sep 2011 13:57:09 -0700 Message-ID: <1316725029-22737-4-git-send-email-ccross@android.com> References: <1316725029-22737-1-git-send-email-ccross@android.com> Cc: linux-fsdevel@vger.kernel.org, Alexander Viro , Ingo Molnar , Peter Zijlstra , Andrew Morton , Alexey Dobriyan , Colin Cross To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1316725029-22737-1-git-send-email-ccross@android.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org seq_files are often used for debugging. When things are going wrong due to failed physically contiguous allocations, the exponentially growing physically contiguous allocations in seq_read can make things worse. There is no need for physically contiguous memory, so switch to virtually contiguous memory instead. Signed-off-by: Colin Cross --- fs/seq_file.c | 23 ++++++++++------------- 1 files changed, 10 insertions(+), 13 deletions(-) diff --git a/fs/seq_file.c b/fs/seq_file.c index 8d9778c..7045656 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -76,15 +77,11 @@ int seq_reserve(struct seq_file *m, size_t size) { void *buf; - /* don't ask for more than the kmalloc() max size */ - if (size > KMALLOC_MAX_SIZE) - size = KMALLOC_MAX_SIZE; - - buf = kmalloc(size, GFP_KERNEL); + buf = vmalloc(size); if (!buf) return -ENOMEM; - kfree(m->buf); + vfree(m->buf); m->buf = buf; m->size = size; @@ -106,7 +103,7 @@ static int traverse(struct seq_file *m, loff_t offset) return 0; } if (!m->buf) { - m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL); + m->buf = vmalloc(m->size = PAGE_SIZE); if (!m->buf) return -ENOMEM; } @@ -145,8 +142,8 @@ static int traverse(struct seq_file *m, loff_t offset) Eoverflow: m->op->stop(m, p); - kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + vfree(m->buf); + m->buf = vmalloc(m->size <<= 1); return !m->buf ? -ENOMEM : -EAGAIN; } @@ -199,7 +196,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) m->version = file->f_version; /* grab buffer if we didn't have one */ if (!m->buf) { - m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL); + m->buf = vmalloc(m->size = PAGE_SIZE); if (!m->buf) goto Enomem; } @@ -239,8 +236,8 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) if (m->count < m->size) goto Fill; m->op->stop(m, p); - kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + vfree(m->buf); + m->buf = vmalloc(m->size <<= 1); if (!m->buf) goto Enomem; m->count = 0; @@ -355,7 +352,7 @@ EXPORT_SYMBOL(seq_lseek); int seq_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; - kfree(m->buf); + vfree(m->buf); kfree(m); return 0; } -- 1.7.4.1