Attachment 150135 Details for Bug 230803 – Tentative patch for sequential read performance fix

[patch] Tentative patch for sequential read performance fix

gfs_ra_perf.patch (text/plain), 4.62 KB, created by Wendy Cheng on 2007-03-15 16:08:41 UTC

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Creator: Wendy Cheng

Created: 2007-03-15 16:08:41 UTC

Size: 4.62 KB

patch

obsolete

>--- gfs-kernel-2.6.9-71/src/gfs/diaper.c	2007-03-14 15:55:25.000000000 -0400
>+++ gfs-kernel/src/gfs/diaper.c	2007-03-15 09:07:55.000000000 -0400
>@@ -27,6 +27,8 @@
> #include "diaper.h"
> #include "ops_fstype.h"
> 
>+#define READAHEAD_DEBUG	1
>+
> struct diaper_holder {
> 	struct list_head dh_list;
> 	unsigned int dh_count;
>@@ -371,6 +373,16 @@ diaper_get(struct block_device *real, in
> 		diaper->bd_inode->i_data.backing_dev_info = &gd->queue->backing_dev_info;
> 	} else
> 		printk("GFS: diaper: reopening\n");
>+
>+#if defined(READAHEAD_DEBUG)
>+	/* gfs readahead fix */
>+	if (!diaper->bd_inode->i_data.backing_dev_info)
>+		printk("GFS: diaper device doesn't have backing_dev_info\n");
>+	else
>+		printk("GFS: diaper device ra_pages = %x\n",
>+			diaper->bd_inode->i_data.backing_dev_info->ra_pages);
>+#endif
>+
> 	diaper->bd_openers++;
> 	up(&diaper->bd_sem);
> 
>--- gfs-kernel-2.6.9-71/src/gfs/gfs.h	2007-03-15 08:18:32.000000000 -0400
>+++ gfs-kernel/src/gfs/gfs.h	2007-03-15 09:07:36.000000000 -0400
>@@ -21,6 +21,7 @@
> 
> #include "fixed_div64.h"
> #include "lvb.h"
>+#include <linux/backing-dev.h>
> #include "incore.h"
> #include "util.h"
> 
>--- gfs-kernel-2.6.9-71/src/gfs/incore.h	2007-03-14 15:55:25.000000000 -0400
>+++ gfs-kernel/src/gfs/incore.h	2007-03-15 08:28:25.000000000 -0400
>@@ -894,6 +894,7 @@ struct gfs_tune {
> 	unsigned int gt_greedy_max;
> 	unsigned int gt_rgrp_try_threshold;
> 	unsigned int gt_statfs_fast;
>+	unsigned int gt_seq_readahead;
> };
> 
> /*
>@@ -959,6 +960,10 @@ struct gfs_sbd {
> 
> 	struct super_block *sd_vfs;     /* Linux VFS device independent sb */
> 
>+	/* readahead */
>+	struct backing_dev_info sd_dev_info;
>+	spinlock_t sd_dev_info_spin;
>+
> 	struct gfs_args sd_args;        /* Mount arguments */
> 	unsigned long sd_flags;         /* SDF_... see above */
> 
>--- gfs-kernel-2.6.9-71/src/gfs/ioctl.c	2007-03-14 15:55:25.000000000 -0400
>+++ gfs-kernel/src/gfs/ioctl.c	2007-03-15 08:31:00.000000000 -0400
>@@ -484,6 +484,7 @@ gi_get_tune(struct gfs_inode *ip,
>         gfs_printf("greedy_max %u\n", gt->gt_greedy_max);
>         gfs_printf("rgrp_try_threshold %u\n", gt->gt_rgrp_try_threshold);
>         gfs_printf("statfs_fast %u\n", gt->gt_statfs_fast);
>+	gfs_printf("seq_readahead %u\n", gt->gt_seq_readahead);
> 
>         error = 0;
> 
>@@ -763,6 +764,14 @@ gi_set_tune(struct gfs_sbd *sdp, struct 
> 		else 
> 			tune_set(gt_statfs_fast, x);
> 
>+	} else if (strcmp(param, "seq_readahead") == 0) {
>+		if (sscanf(value, "%u", &x) != 1)
>+			return -EINVAL;
>+		error = gfs_reset_readahead(sdp, x);
>+		if (error)
>+			return error;
>+		tune_set(gt_seq_readahead, x);
>+
> 	} else
> 		return -EINVAL;
> 
>--- gfs-kernel-2.6.9-71/src/gfs/super.h	2007-03-14 15:55:25.000000000 -0400
>+++ gfs-kernel/src/gfs/super.h	2007-03-15 08:32:28.000000000 -0400
>@@ -63,4 +63,6 @@ int gfs_lock_fs_check_clean(struct gfs_s
> int gfs_freeze_fs(struct gfs_sbd *sdp);
> void gfs_unfreeze_fs(struct gfs_sbd *sdp);
> 
>+int gfs_reset_readahead(struct gfs_sbd *sdp, unsigned int file_ra);
>+
> #endif /* __SUPER_DOT_H__ */
>--- gfs-kernel-2.6.9-71/src/gfs/ops_file.c	2007-03-14 15:55:25.000000000 -0400
>+++ gfs-kernel/src/gfs/ops_file.c	2007-03-15 09:16:44.000000000 -0400
>@@ -1743,6 +1743,57 @@ gfs_flock(struct file *file, int cmd, st
> 		return do_flock(file, cmd, fl);
> }
> 
>+/*
>+ * VFS layer offers a "bd_inode_backing_dev_info" pointer to allow
>+ * filesystem overriding its block device generic readahead value.
>+ * We'll take this advantage to tune for large sequential write.
>+ */
>+struct backing_dev_info gfs_file_backing_dev_info = {
>+        .ra_pages       = 0,    /* place holder */
>+        .memory_backed  = 0,    /* place holder */
>+        .unplug_io_fn   = default_unplug_io_fn,
>+};
>+
>+int gfs_reset_readahead(struct gfs_sbd *sdp, unsigned int file_ra)
>+{
>+	unsigned int max_ra;
>+	struct backing_dev_info *bdi;
>+	struct super_block *vfs_sb=sdp->sd_vfs;
>+
>+	/* user wants to reset back to default */
>+	if (file_ra == 0) {
>+		vfs_sb->s_bdev->bd_inode_backing_dev_info = NULL;
>+		return 0;
>+	}
>+
>+	/* can't exceed gfs max readahead */
>+	max_ra = gfs_tune_get(sdp, gt_max_readahead);
>+	if (file_ra > max_ra) {
>+		printk("GFS: einval - readahead exceeds max\n");
>+		return -EINVAL;
>+	}
>+
>+	bdi = sdp->sd_vfs->s_bdev->bd_inode_backing_dev_info;
>+
>+	/* sanity check */
>+	if (gfs_tune_get(sdp, gt_seq_readahead) && !bdi) {
>+		printk("GFS: error - gt_seq_readahead set but bdi is NULL\n");
>+		return -EIO;
>+	}
>+		
>+	/* add pointer */
>+	if (!bdi) {
>+		bdi = &sdp->sd_dev_info;
>+		vfs_sb->s_bdev->bd_inode_backing_dev_info = bdi;
>+		*bdi = *(vfs_sb->s_bdev->bd_inode->i_data.backing_dev_info);
>+	}
>+
>+	/* now change the setting */
>+	bdi->ra_pages = file_ra;
>+
>+	return 0;
>+}
>+
> struct file_operations gfs_file_fops = {
> 	.llseek = gfs_llseek,
> 	.read = gfs_read,

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Attachments on bug 230803: 150135