perf-mem(1)
===========

NAME
----
perf-mem - Profile memory accesses

SYNOPSIS
--------
[verse]
'perf mem' [<options>] (record [<command>] | report)

DESCRIPTION
-----------
"perf mem record" runs a command and gathers memory operation data
from it, into perf.data. Perf record options are accepted and are passed through.

"perf mem report" displays the result. It invokes perf report with the
right set of options to display a memory access profile. By default, loads
and stores are sampled. Use the -t option to limit to loads or stores.

Note that on Intel systems the memory latency reported is the use-latency,
not the pure load (or store latency). Use latency includes any pipeline
queueing delays in addition to the memory subsystem latency.

OPTIONS
-------
<command>...::
	Any command you can specify in a shell.

-t::
--type=::
	Select the memory operation type: load or store (default: load,store)

-D::
--dump-raw-samples=::
	Dump the raw decoded samples on the screen in a format that is easy to parse with
	one sample per line.

-x::
--field-separator::
	Specify the field separator used when dump raw samples (-D option). By default,
	The separator is the space character.

-C::
--cpu-list::
	Restrict dump of raw samples to those provided via this option. Note that the same
	option can be passed in record mode. It will be interpreted the same way as perf
	record.

-K::
--all-kernel::
	Configure all used events to run in kernel space.

-U::
--all-user::
	Configure all used events to run in user space.

--ldload::
	Specify desired latency for loads event.

SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1]
nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>refs</a><a href='/cgit.cgi/linux/net-next.git/log/drivers/usb/host?h=nds-private-remove'>log</a><a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>tree</a><a class='active' href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/drivers/usb/host'>
<input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='08965c2eba135bdfb6e86cf25308e01421c7e0ce'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>host</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='08965c2eba135bdfb6e86cf25308e01421c7e0ce'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;</td><td class='right'>2017-01-25 13:43:56 -0800</td></tr>
<tr><th>committer</th><td>Jens Axboe &lt;axboe@fb.com&gt;</td><td class='right'>2017-01-26 10:01:20 -0700</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>08965c2eba135bdfb6e86cf25308e01421c7e0ce</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/host?id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>1675b0e264e8a23efe04ea48f44b00c10506f2a6</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>drivers/usb/host</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/host?h=nds-private-remove&amp;id=0d4ee015d5ea50febb882d00520d62c6de3f725c'>0d4ee015d5ea50febb882d00520d62c6de3f725c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/host?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce&amp;id2=0d4ee015d5ea50febb882d00520d62c6de3f725c'>diff</a>)</td></tr></table>
<div class='commit-subject'>Revert "sd: remove __data_len hack for WRITE SAME"</div><div class='commit-msg'>This patch reverts commit f80de881d8df and avoids that sending a
WRITE SAME command to the iSCSI initiator triggers the following:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000014
TARGET_CORE[iSCSI]: Expected Transfer Length: 260096 does not match SCSI CDB Length: 512 for SAM Opcode: 0x41
IP: iscsi_tcp_segment_done+0x20b/0x310 [libiscsi_tcp]

Oops: 0000 [#1] SMP
Modules linked in: target_core_user uio target_core_iblock target_core_file iscsi_target_mod target_core_mod netconsole configfs crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 crypto_simd cryptd glue_helper virtio_console virtio_rng virtio_balloon serio_raw i2c_piix4 acpi_cpufreq button iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ext4 jbd2 mbcache virtio_blk virtio_net psmouse floppy drm_kms_helper syscopyarea
sysfillrect sysimgblt fb_sys_fops ttm drm virtio_pci
CPU: 2 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0-rc5-debug+ #3
Workqueue: iscsi_q_0 iscsi_xmitworker [libiscsi]
RIP: 0010:iscsi_tcp_segment_done+0x20b/0x310 [libiscsi_tcp]
Call Trace:
 iscsi_sw_tcp_xmit_segment+0x84/0x120 [iscsi_tcp]
 iscsi_sw_tcp_pdu_xmit+0x51/0x180 [iscsi_tcp]
 iscsi_tcp_task_xmit+0xb3/0x290 [libiscsi_tcp]
 iscsi_xmit_task+0x4e/0xc0 [libiscsi]
 iscsi_xmitworker+0x243/0x330 [libiscsi]
 process_one_work+0x1d8/0x4b0
 worker_thread+0x49/0x4a0
 kthread+0x102/0x140

Fixes: f80de881d8df ("sd: remove __data_len hack for WRITE SAME")
Signed-off-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Cc: Hannes Reinecke &lt;hare@suse.com&gt;
Cc: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Cc: Jens Axboe &lt;axboe@fb.com&gt;
Cc: Lee Duncan &lt;lduncan@suse.com&gt;
Cc: Chris Leech &lt;cleech@redhat.com&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=08965c2eba135bdfb6e86cf25308e01421c7e0ce'>Diffstat</a> (limited to 'drivers/usb/host')</div><table summary='diffstat' class='diffstat'>