Commit 8a072a4d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Alex Elder
Browse files

xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy 



Instead of finding the per-ag and then taking and releasing the pagb_lock
for every single busy extent completed sort the list of busy extents and
only switch betweens AGs where nessecary.  This becomes especially important
with the online discard support which will hit this lock more often.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent 97d3ac75

fs/xfs/linux-2.6/xfs_buf.c

+0 −1
Original line number Diff line number Diff line
@@ -33,7 +33,6 @@ 
#include <linux/migrate.h>

#include <linux/backing-dev.h>

#include <linux/freezer.h>

#include <linux/list_sort.h>



#include "xfs_sb.h"

#include "xfs_inum.h"

fs/xfs/linux-2.6/xfs_linux.h

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ 
#include <linux/ctype.h>

#include <linux/writeback.h>

#include <linux/capability.h>

#include <linux/list_sort.h>



#include <asm/page.h>

#include <asm/div64.h>

fs/xfs/xfs_alloc.c

+46 −10
Original line number Diff line number Diff line
@@ -2964,24 +2964,60 @@ fail: 
	*rlen = 0;

}



void

xfs_alloc_busy_clear(

static void

xfs_alloc_busy_clear_one(

	struct xfs_mount	*mp,

	struct xfs_perag	*pag,

	struct xfs_busy_extent	*busyp)

{

	struct xfs_perag	*pag;

	if (busyp->length) {

		trace_xfs_alloc_busy_clear(mp, busyp->agno, busyp->bno,

						busyp->length);

		rb_erase(&busyp->rb_node, &pag->pagb_tree);

	}



	list_del_init(&busyp->list);

	kmem_free(busyp);

}



void

xfs_alloc_busy_clear(

	struct xfs_mount	*mp,

	struct list_head	*list)

{

	struct xfs_busy_extent	*busyp, *n;

	struct xfs_perag	*pag = NULL;

	xfs_agnumber_t		agno = NULLAGNUMBER;



	list_for_each_entry_safe(busyp, n, list, list) {

		if (busyp->agno != agno) {

			if (pag) {

				spin_unlock(&pag->pagb_lock);

				xfs_perag_put(pag);

			}

			pag = xfs_perag_get(mp, busyp->agno);

			spin_lock(&pag->pagb_lock);

	if (busyp->length) {

		trace_xfs_alloc_busy_clear(mp, busyp->agno, busyp->bno,

						busyp->length);

		rb_erase(&busyp->rb_node, &pag->pagb_tree);

			agno = busyp->agno;

		}



		xfs_alloc_busy_clear_one(mp, pag, busyp);

	}



	if (pag) {

		spin_unlock(&pag->pagb_lock);

		xfs_perag_put(pag);

	}

}



	kmem_free(busyp);

/*

 * Callback for list_sort to sort busy extents by the AG they reside in.

 */

int

xfs_busy_extent_ag_cmp(

	void			*priv,

	struct list_head	*a,

	struct list_head	*b)

{

	return container_of(a, struct xfs_busy_extent, list)->agno -

		container_of(b, struct xfs_busy_extent, list)->agno;

}

fs/xfs/xfs_alloc.h

+10 −1
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, 
	xfs_agblock_t bno, xfs_extlen_t len);



void

xfs_alloc_busy_clear(struct xfs_mount *mp, struct xfs_busy_extent *busyp);

xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list);



int

xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno,
@@ -149,6 +149,15 @@ xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, 
void

xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno,

	xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata);



int

xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b);



static inline void xfs_alloc_busy_sort(struct list_head *list)

{

	list_sort(NULL, list, xfs_busy_extent_ag_cmp);

}



#endif	/* __KERNEL__ */



/*

fs/xfs/xfs_log_cil.c

+2 −3
Original line number Diff line number Diff line
@@ -361,13 +361,12 @@ xlog_cil_committed( 
	int	abort)

{

	struct xfs_cil_ctx	*ctx = args;

	struct xfs_busy_extent	*busyp, *n;



	xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain,

					ctx->start_lsn, abort);



	list_for_each_entry_safe(busyp, n, &ctx->busy_extents, list)

		xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, busyp);

	xfs_alloc_busy_sort(&ctx->busy_extents);

	xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, &ctx->busy_extents);



	spin_lock(&ctx->cil->xc_cil_lock);

	list_del(&ctx->committing);

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