Unverified Commit aabcabf2 authored by David Howells's avatar David Howells Committed by Christian Brauner
Browse files

netfs: Add a tracepoint to log the lifespan of folio_queue structs 



Add a tracepoint to log the lifespan of folio_queue structs.  For tracing
illustrative purposes, folio_queues are tagged with the debug ID of
whatever they're related to (typically a netfs_io_request) and a debug ID
of their own.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-5-dhowells@redhat.com


cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent eb118159

fs/netfs/buffered_read.c

+7 −3
Original line number Diff line number Diff line
@@ -131,7 +131,8 @@ static ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq) 
			struct folio_queue *tail = rreq->buffer_tail, *new;

			size_t added;



			new = netfs_folioq_alloc(GFP_NOFS);

			new = netfs_folioq_alloc(rreq->debug_id, GFP_NOFS,

						 netfs_trace_folioq_alloc_read_prep);

			if (!new)

				return -ENOMEM;

			new->prev = tail;
@@ -361,9 +362,11 @@ static int netfs_prime_buffer(struct netfs_io_request *rreq) 
	struct folio_batch put_batch;

	size_t added;



	folioq = netfs_folioq_alloc(GFP_KERNEL);

	folioq = netfs_folioq_alloc(rreq->debug_id, GFP_KERNEL,

				    netfs_trace_folioq_alloc_read_prime);

	if (!folioq)

		return -ENOMEM;



	rreq->buffer = folioq;

	rreq->buffer_tail = folioq;

	rreq->submitted = rreq->start;
@@ -436,7 +439,8 @@ static int netfs_create_singular_buffer(struct netfs_io_request *rreq, struct fo 
{

	struct folio_queue *folioq;



	folioq = netfs_folioq_alloc(GFP_KERNEL);

	folioq = netfs_folioq_alloc(rreq->debug_id, GFP_KERNEL,

				    netfs_trace_folioq_alloc_read_sing);

	if (!folioq)

		return -ENOMEM;

fs/netfs/internal.h

+2 −1
Original line number Diff line number Diff line
@@ -58,7 +58,8 @@ static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} 
/*

 * misc.c

 */

struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq);

struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,

					    enum netfs_folioq_trace trace);

int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio,

			      bool needs_put);

struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq);

fs/netfs/misc.c

+20 −11
Original line number Diff line number Diff line
@@ -10,18 +10,25 @@ 


/**

 * netfs_folioq_alloc - Allocate a folio_queue struct

 * @rreq_id: Associated debugging ID for tracing purposes

 * @gfp: Allocation constraints

 * @trace: Trace tag to indicate the purpose of the allocation

 *

 * Allocate, initialise and account the folio_queue struct.

 * Allocate, initialise and account the folio_queue struct and log a trace line

 * to mark the allocation.

 */

struct folio_queue *netfs_folioq_alloc(gfp_t gfp)

struct folio_queue *netfs_folioq_alloc(unsigned int rreq_id, gfp_t gfp,

				       unsigned int /*enum netfs_folioq_trace*/ trace)

{

	static atomic_t debug_ids;

	struct folio_queue *fq;



	fq = kmalloc(sizeof(*fq), gfp);

	if (fq) {

		netfs_stat(&netfs_n_folioq);

		folioq_init(fq);

		folioq_init(fq, rreq_id);

		fq->debug_id = atomic_inc_return(&debug_ids);

		trace_netfs_folioq(fq, trace);

	}

	return fq;

}
@@ -30,11 +37,14 @@ EXPORT_SYMBOL(netfs_folioq_alloc); 
/**

 * netfs_folioq_free - Free a folio_queue struct

 * @folioq: The object to free

 * @trace: Trace tag to indicate which free

 *

 * Free and unaccount the folio_queue struct.

 */

void netfs_folioq_free(struct folio_queue *folioq)

void netfs_folioq_free(struct folio_queue *folioq,

		       unsigned int /*enum netfs_trace_folioq*/ trace)

{

	trace_netfs_folioq(folioq, trace);

	netfs_stat_d(&netfs_n_folioq);

	kfree(folioq);

}
@@ -43,7 +53,8 @@ EXPORT_SYMBOL(netfs_folioq_free); 
/*

 * Make sure there's space in the rolling queue.

 */

struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq)

struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,

					    enum netfs_folioq_trace trace)

{

	struct folio_queue *tail = rreq->buffer_tail, *prev;

	unsigned int prev_nr_slots = 0;
@@ -59,11 +70,9 @@ struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq) 
		prev_nr_slots = folioq_nr_slots(tail);

	}



	tail = kmalloc(sizeof(*tail), GFP_NOFS);

	tail = netfs_folioq_alloc(rreq->debug_id, GFP_NOFS, trace);

	if (!tail)

		return ERR_PTR(-ENOMEM);

	netfs_stat(&netfs_n_folioq);

	folioq_init(tail);

	tail->prev = prev;

	if (prev)

		/* [!] NOTE: After we set prev->next, the consumer is entirely
@@ -98,7 +107,7 @@ int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio 
	struct folio_queue *tail;

	unsigned int slot, order = folio_order(folio);



	tail = netfs_buffer_make_space(rreq);

	tail = netfs_buffer_make_space(rreq, netfs_trace_folioq_alloc_append_folio);

	if (IS_ERR(tail))

		return PTR_ERR(tail);
@@ -119,7 +128,7 @@ struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq) 


	if (next)

		next->prev = NULL;

	netfs_folioq_free(head);

	netfs_folioq_free(head, netfs_trace_folioq_delete);

	wreq->buffer = next;

	return next;

}
@@ -142,7 +151,7 @@ void netfs_clear_buffer(struct netfs_io_request *rreq) 
				folio_put(folio);

			}

		}

		netfs_folioq_free(p);

		netfs_folioq_free(p, netfs_trace_folioq_clear);

	}

}

fs/netfs/read_collect.c

+6 −2
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was 
		 subreq->transferred, subreq->len))

		subreq->transferred = subreq->len;



	trace_netfs_folioq(folioq, netfs_trace_folioq_read_progress);

next_folio:

	fsize = PAGE_SIZE << subreq->curr_folio_order;

	fpos = round_down(subreq->start + subreq->consumed, fsize);
@@ -119,9 +120,11 @@ static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was 
		if (folioq) {

			struct folio *folio = folioq_folio(folioq, slot);



			pr_err("folioq: orders=%02x%02x%02x%02x\n",

			pr_err("folioq: fq=%x orders=%02x%02x%02x%02x %px\n",

			       folioq->debug_id,

			       folioq->orders[0], folioq->orders[1],

			       folioq->orders[2], folioq->orders[3]);

			       folioq->orders[2], folioq->orders[3],

			       folioq);

			if (folio)

				pr_err("folio: %llx-%llx ix=%llx o=%u qo=%u\n",

				       fpos, fend - 1, folio_pos(folio), folio_order(folio),
@@ -222,6 +225,7 @@ static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was 
			slot = 0;

			folioq = folioq->next;

			subreq->curr_folioq = folioq;

			trace_netfs_folioq(folioq, netfs_trace_folioq_read_progress);

		}

		subreq->curr_folioq_slot = slot;

		if (folioq && folioq_folio(folioq, slot))

fs/netfs/write_issue.c

+1 −1
Original line number Diff line number Diff line
@@ -161,7 +161,7 @@ static void netfs_prepare_write(struct netfs_io_request *wreq, 
	 */

	if (iov_iter_is_folioq(wreq_iter) &&

	    wreq_iter->folioq_slot >= folioq_nr_slots(wreq_iter->folioq)) {

		netfs_buffer_make_space(wreq);

		netfs_buffer_make_space(wreq, netfs_trace_folioq_prep_write);

	}



	subreq = netfs_alloc_subrequest(wreq);